The key to winning baseball has always been pitching and the New York Yankees solidified their 2014 starting rotation by agreeing to terms with Japanese right-hander Masahiro Tanaka on Thursday.

After a disastrous season in which the Yankees failed to make the playoffs for only the second time in 19 seasons, their stated “goal” of remaining under the $189 million payroll limit and the loss of Robinson Cano to free agency, managing general partner Hal Steinbrenner fought back by loosening the pursestrings for general manager Brian Cashman.

The result was a dizzying array of signings that included All-Star catcher Brian McCann, outfielders Jacoby Ellsbury and Carlos Beltran, the additions of key pieces like infielders Brian Roberts and Kelly Johnson and left-handed reliever Matt Thornton and the re-signing of right-handed starter Hiroki Kuroda.

But none of those signings would have mattered much at all unless the Yankees landed Tanaka.

Tanaka, 25, came off a season with Rakuten Golden Eagles with a 24-0 record and a 1.27 ERA in leading his team to the Japanese championship. In his seven seasons he was 99-35 with a 2.30 ERA, striking out 1,238 batters in 1,315 innings.

The right-hander possesses a 94-mile-per-hour fastball along with a world-class splitter and a slider. More importantly, Tanaka is not a nibbler in the tradition of Daisuke Matsuzaka. Last season he struck out 183 batters while walking 32 in 212 innings.

Those eye-popping stats led the Yankees front office to offer a seven-year contract worth $155 million plus the $20 million posting fee that will have to be paid to the Golden Eagles. The signing also proved pundits wrong for predicting that the Los Angeles Dodgers had the inside track in signing Tanaka because his wife, a singing star of some note, preferred to be on the West Coast and craved the glitter of Hollywood.

Tanaka will receive $22 million in each of the first six seasons and $23 million in 2020. The deal also allows the contract to be terminated after four seasons to permit Tanaka to seek free agency. He also has a full no-trade clause.

He also was allotted a $35,000 moving allowance and annual payments of $100,000 per season for housing for the New York metropolitan area or Tampa, FL. The Yankees threw in $85,000 in annual salary for an interpreter and four annual first-class flights from the United States to Japan.

Doubters will question this largesse heaped upon a pitcher who has yet to throw a pitch in the major leagues. But the Yankees’ front office and scouts were convinced that Tanaka has the potential to be even better than countryman Yu Darvish, 27, who is 29-18 with a 3.34 ERA in his first two seasons as the ace of the Texas Rangers.

Tanaka will slide into the No. 2 spot behind CC Sabathia and join fellow Japanese right-hander Kuroda and 27-year-old right-hander Ivan Nova in a revamped Yankee rotation in 2014.

The Yankees believed they needed to upgrade the rotation this season after the retirement of left-hander Andy Pettitte and the loss of right-hander Phil Hughes to the Minnesota Twins.

There also are questions swirling around Sabathia, 33, after his disappointing 2013 campaign in which he slipped to 14-13 with a 4.78 ERA. The ace left-hander had to adjust with a huge drop in velocity on his fastball and his record shows there are more adjustments necessary.

But Sabathia vows that he will show up this spring ready to prove he is still the same pitcher who was 74-29 in his previous four seasons in pinstripes.

That would be a good thing because Sabathia never found his groove after posting a 4-2 record with a 3.35 ERA in April. His ERAs in succeeding months were 4.14, 5.11, 6.60 and 5.94. Yankee fans can take some comfort in the fact Sabathia was 2-2 with a 3.90 ERA in September.

That could indicate he will indeed adjust as Pettitte and Mike Mussina did when they lost velocity.

The odd thing is that after four seasons of being accused of not paying attention to his weight as the season progressed, many of those same “so-called experts” thought Sabathia lost velocity last season because he was too thin. Well, who really knows? But it is ironic those “experts” would mention it.

The Yankees will settle for Sabathia arriving in Tampa in shape and they believe he has enough weapons to remain effective as a starting pitcher because he never really has been a pitcher totally dependent on his fastball to get by.

He will remain atop the rotation in 2014 with the help of the infusion of a young Tanaka behind him.

Strangely, the Yankees’ No. 3 starter was their best pitcher in 2013 despite making only 20 starts.

Nova began the season pitching horribly in spring training and in his first four starts of 2013 before succumbing to a inflammation in right triceps. After spending time on the disabled list, a rehab stint in the minors and pitching briefly out of the bullpen, Nova returned to the rotation on June 23.

From that point on, Nova was absolutely brilliant. He was 7-4 with a 2.59 in his last 15 starts beginning on July 5. This came after a season in which Nova’s game flew off the rails and he ended up 12-8 with a 5.02 ERA in 2012.

So the Yankees believe that Nova’s second half is more indicative of what he is as a pitcher after he was 16-4 with a 3.70 ERA in 2011.

Nova decided not to use his slider very much last season in order to concentrate on his mid-90s fastball and devastating curveball. The result was 79 strikeouts in those 15 starts. The fact that he still just 27 makes him an excellent No. 3 starter in this bolstered rotation.

Before Nova came on, Kuroda, who will be 39 on Feb. 10, was the Yankees’ most consistent pitcher. In fact, on Aug. 12, Kuroda was sporting a 11-7 mark with a 2.33 ERA on one of the weakest hitting Yankee teams in generations.

But a heavy workload of 154 2/3 innings began to take a toll on the veteran. In his last eight starts, Kuroda was 0-6 with a awful 6.56 ERA. It is clear that Kuroda was overtaxed into pitching past six innings too early in the season because he was not getting adequate offensive support.

Manager Joe Girardi was forced to keep him in a lot of close games and Kuroda paid a heavy price down the stretch. Even still, Kuroda finished the season 11-13 with a 3.31 ERA and he will certainly benefit from an improved offense in 2014.

The Yankees are impressed with the way Kuroda is able to adjust midstream in games by dipping into his arsenal of fastballs, sliders, splitters and curves to find the pitches that are working best for him that night, That is why they chose to re-sign him to a third one-year contract for $16 million.

Kuroda and outfielder Ichiro Suzuki should also help make Tanaka feel at home in the Yankees’ clubhouse.

The big concern for the Yankees now is who will claim the No. 5 spot in the rotation. Fortunately, they have some options to fill the spot.

The “dream scenario” for the Yankees would have 25-year-old right-hander Michael Pineda ready to take the ball this spring and run with it. Pineda, after all, was obtained in a 2012 trade with the Seattle Mariners along with right-hander Jose Campos, 21, for catcher Jesus Montero and right-hander Hector Noesi.

However, after a 2011 rookie season in which Pineda made the American League All-Star team and was 9-10 with a 3.74 ERA for a weak-hitting Seattle team, Pineda ended up having to undergo surgery for a torn labrum in his right shoulder after his last spring training start in 2012.

He missed the entire season and pitched only 40 2/3 innings in the minors last season until he was shut down in August after experiencing some minor shoulder soreness.

The Yankees still have high hopes for Pineda, who boasted a mid-90s fastball, an above average change-up and a slider before his injury. The Yankees took a lot of heat from their fans when they traded away their No. 1 prospect in Montero and allowed the Mariners to deal Pineda instead of parting with ace right-hander Felix Hernandez.

So there is some pressure on Pineda as he enters spring training having not thrown a single pitch for the Yankees in two seasons. It will be interesting to see how much Pineda has lost off his heater and if he still can be effective for the Yankees.

But the Yankees claim he is healthy and should be ready to go.

Another option for the No. 5 spot is right-hander David Phelps.

Phelps, 27, started his second major-league season in his usual role as a long man in the bullpen until he was thrust into the rotation on May 1 to replace the injured Nova.

Phelps showed great promise by going 2-2 with a 4.32 in six starts in May. But he stumbled to a 3-2 record with a 5.57 ERA in his next six starts before he landed on the disabled list in July with a strained right forearm.

Phelps did not return to the roster until Sept. 15 and was 0-0 with a 4.50 ERA in four relief appearances.

The Yankees see Phelps as a solid Plan B if Pineda is not quite ready to pitch or he suffers a setback in his rehab. But the Yankees clearly see Phelps more valuable in the bullpen, as his numbers in 2012 indicate. Phelps was 4-4 with a 4.34 ERA in his rookie season.

Girardi and pitching coach Larry Rothschild admire Phelps fearlessness in attacking hitters though he owns only a pedestrian fastball.

Phelps makes up for a lack of velocity with good command of the strike zone and he can ring up a lot of strikeouts with his breaking stuff and pitching smarts.

The Yankees also have right-hander Adam Warren, 26, who was 2-2 with a 3.39 ERA in a long relief role for the Yankees in his rookie season in 2013.

Warren did make two late-season spot starts and was 1-0 with a 2.25 ERA in those starts. Unlike Phelps, Warren has above-average velocity on his fastball. But the Yankees are not sure how high Warren’s ceiling extends as a starter. They would prefer to keep him as a long reliever if they could.

The Yankees got an unexpected boost with a reclamation project in left-hander David Huff last season. Huff, 29, who was former starter with the Cleveland Indians, was signed after his release from the Indians and recalled from Triple-A Scranton Wilkes-Barre in mid-August.

He was 3-1 with a 4.67 ERA. But that does not tell the whole story. Huff was tagged for nine runs in 3 1/3 innings against the Boston Red Sox on Sept. 7. Without that disastrous appearance Huff had a 2.37 ERA in his other nine appearances.

Huff also seemed comfortable in a long relief role as well as in his two spot starts in September. He also brings some value as a left-hander.

However, because the Yankees have to make room on the 40-man roster for Tanaka, Huff was designated for assignment. He will only return to the Yankees as a free agent if he is unable to find work elsewhere, which is unlikely considering he is left-handed and he pitched so well in 2013 for the Yankees.

There has been an ongoing rumor this winter that the Yankees might be interested in signing former two-time American League Cy Young Award winner Johan Santana.

Santana, 34, became a free agent when the New York Mets declined to pick up his option for 2014. Santana did not pitch in 2013 after suffering a second tear of his anterior left shoulder capsule. Santana was 46-34 with a 3.18 ERA over parts of four seasons with the Mets.

The signing of Tanaka makes Santana’s signing less likely. Santana was scheduled to make $25 million before the Mets bought out his option for $5.5 million. If the Yankees can get him for less than $10 million they might take a shot. But Santana also has to prove he is healthy.

The Twins, the team with whom he won those two Cy Young awards, are among the teams interested in Santana when he is given the go-ahead to throw from a mound for scouts at his Fort Myers, FL, home in February.

The Yankees do have some good young pitchers in the minors but none of them look ready to break camp with the team. A few could be called up during the season if they progress well.

At the top of the list is left-hander Vidal Nuno, 26, who was the Yankees top rookie of spring training in 2013.

Nuno was 2-0 with a 1.44 ERA at Scranton and he received a midseason call-up to the Yankees. In five appearances, including three starts, Nuno was 1-2 with a 2.25 ERA. He missed most of the remainder of the season with a strained left groin.

For some reason Nuno is able to keep batters off-balance with a mix of breaking stuff that he features with a very lackluster upper 80s fastball. The reason is he has pinpoint control. He walked only eight batters in his combined 45 minor- and major-league innings in 2013.

If he has another strong showing this spring, Nuno could certainly leapfrog Phelps or Warren for the No. 5 spot. In addition, he could also make the squad as a long reliever and spot starter. Girardi loves pitchers who challenge hitters and don’t issue walks.

This spring all eyes will be on 22-year-old left-hander Manny Banuelos, who missed the entire 2013 season recovering from Tommy John surgery.

Banuelos was considered the team’s No. 1 prospect at the time he was injured in 2012. In 2011, Banuelos was 1-1 with 2.13 ERA in 12 2/3 innings in spring training, earning him the James P. Dawson Award as the Yankees’ top rookie.

However, the young Mexican lefty struggled with his control in 2011, walking 71 batters in a cobined 129 2/3 innings between Double-A Trenton and Scranton. He was 6-7 with a 3.45 ERA that season.

In 2012, he made only six starts before being shelved with elbow soreness and he ended up having to undergo surgery to repair a ligament in his left elbow in October.

The Yankees love his low-90s fastball and change-up combination that saw him strike out 125 batters in 2011. He is still young and talented enough to progress quickly if he puts it all together. But the Yankees would like to see him do that at Scranton before they bring him up to the big club.

He remains the team’s No. 8 prospect. He just has to prove he is healthy and regain his control.

The Yankees are also very high on 24-year-old right-hander Jose Ramirez, who was 1-3 with a 2.76 ERA in eight starts at Trenton before going 1-3 with a 4.88 ERA in eight starts at Scranton. Ramirez struck out 78 batters in 73 2/3 innings and the Yankees believe he has a very high ceiling.

But he likely needs a full season at Scranton before he makes a bid for the big club.

The same can be said for left-hander Nik Turley, 24.

Turley, a relative of former Yankees right-hander Bob Turley, was 11-8 with a 3.88 ERA in 26 starts at Trenton last season. Compared to Pettitte in style, teammates call him “Little Andy” and he backed that up by fanning 137 batters in 139 innings last season.

Below Banuelos, Ramirez and Turley the Yankees have a nice corps of young starters who are a few years away from making it to the majors.

The biggest buzz is surrounding the team’s No. 4 prospect Rafael De Paula, 22.

The 6-foot-2, 215-pound right-hander hits up to 99-mph on his fastball and he has a hard curve and a change-up. He was a combined 7-5 with a 4.29 ERA at High-A Tampa and Charleston last season. More impressive was his 146 punch-outs in only 113 1/3 innings.

DePaula enters the 2014 season as the team’s best young arm and deservedly so. This young Dominican has quality starter written all over him.

Don’t forget about the right-handed Campos, either. Campos, 21, was obtained along with Pineda in the Montero deal and he may have even an higher ceiling than Pineda.

Campos suffered an elbow injury that did not require surgery in 2012, In 2013, he was 4-2 with a 3.41 ERA in 26 games (19 starts) at Charleston. He has an above-average fastball to go along with very good control of two secondary pitches.

That mix will take him far as long he can prove he can stay healthy in 2014.

The Yankees also have high hopes for 22-year-old right-handed flamethrower Bryan Mitchell, who likely will be at Trenton this season. Mitchell was 4-11 with a 4.71 ERA at Tampa and Trenton last season. The Yankees need only to see him command his 96-mph fastball and nearly unhittable curve to make a giant leap this season.

Two others to watch are 2013 first-round draft pick Ian Clarkin, a left-hander, and 20-year-old right-hander Ty Hensley, who was picked in the first round in 2012.

Unlike the position players, the Yankees are pretty rich in young starters at the minor-league level. It is quite possible that three or four of them could be strong contributors with the big club very soon.

In the meantime, the signing of Tanaka has given the Yankees a major shot in the arm. Just ask the rival Boston Red Sox. They see that the $471 million the team has spent on free agents has thrust them back among the top tier teams in the American League East.

Without pitching it is hard to compete in such a tough division. It appears now the Yankees will have a starting staff that can get them back to the playoffs.

That would require one huge “arigato” (thank you in Japanese) to the signing of Tanaka.