Patrick Corbin is in his first Nationals spring training after signing a lucrative six-year contract in December. (Toni L. Sandys/The Washington Post)

WEST PALM BEACH, Fla. — The last time Patrick Corbin was the new kid in the clubhouse, he was 22 years old, not yet a two-time all-star, not yet worth $140 million to a team hitching at least some of its World Series hopes to his left arm.

A lot has changed. And maybe a lot hasn’t.

“I mean, it’s the same game,” Corbin said Thursday. “So you try to have your same routine and do that.”

Here is the routine the Washington Nationals are banking on: Corbin takes the ball, Corbin mows through opposing lineups, Corbin gives them a chance to win every start because his six-year deal was twice as lucrative as the next-biggest deal this offseason. They want that to feel like clockwork. A lot hinges on it.

But Corbin’s also had a knack for surprises throughout a baseball career that didn’t really start until his junior year of high school in Syracuse, N.Y., when he tried out for the varsity team as a lanky basketball player who thought he might be able to pitch. Just ask Kevin Rockwell, Cicero-North High School’s baseball coach, who watched Corbin not lose a game in two seasons. Ask John Haas, Cicero-North’s varsity basketball coach, who once saw Corbin try to throw a cross-court pass that instead swished through the net for a three-pointer. Ask Dave Kernan, his high school catcher, who often had to shift his glove at the last millisecond to track the late movement of Corbin’s fastball.

They’ll all tell you. Corbin is many things — a tall left-handed starter, an elite athlete, possessor of a slider that is widely considered to be one of the best pitches in the majors. But he still flies under the radar at times, if only because of his humble and quiet nature, and he’s approaching his first Nationals spring training the same way.

“That’s just Pat,” said Mike Meola, his high school teammate and now an assistant baseball coach at Le Moyne College in Syracuse. “If he had it his way I don’t think he’d ever talk about himself. Everyone wants him to because he’s such a great pitcher and become a big deal. But Pat would never think of himself that way. He just sort of comes out of nowhere and it’s like: ‘Wow. He did what?’"

Success has sprung Corbin’s life into transition, with a new team, new spring training city and soon a new offseason home. He and his wife, Jen, came to West Palm Beach a week early to look at houses. They are relocating from Arizona to Florida for future offseasons, since Corbin is no longer with the Diamondbacks and now they can be closer to where they both grew up in Central New York.

They were married this past November; Corbin’s free agency disrupted their honeymoon plans. They visited with the Nationals, Philadelphia Phillies and New York Yankees, three of the many teams interested in signing Corbin, before he agreed to a deal with Washington on Dec. 4. But a few weeks earlier he was the same old Pat, swapping old high school stories at his wedding, then challenging his friends to games of knockout a day later on the basketball court in his backyard.

He competed hard. And he won.

“It’s a cliche to say that a guy doesn’t change when he makes it big or makes the big money,” said Haas, who helped Corbin the basketball player develop into Cicero-North’s all-time leader in three-pointers. “But that’s how it is with Pat. You’d never know he was that guy, because he really isn’t in most ways. He keeps showing he’s even better than people think because he would never tell you how good he was in the first place.”

Now he has to be great.

Not just because the Nationals are paying him so much, and not just because his deal is the biggest of the offseason. But because it is, to this point, is the only outsize contract in a winter that was supposed to be full of them. Bryce Harper has yet to sign. Neither has Manny Machado, Craig Kimbrel or Dallas Keuchel, a former Cy Young Award winner and the other marquee lefty starter on the market. Corbin, however, got the Nationals to invest both a lot of money and a lot of years for him to improve a rotation that already had Max Scherzer and Stephen Strasburg.

“Um . . . I don’t know. I’ve always just tried to have a routine and go out there and compete every fifth day, and that’s really what I’m focusing on,” Corbin said when asked if the context of his contract adds any pressure. “It’s good that that is over with and I will be here for six years, so I just need to come in here every day and try to get better and try to win ballgames.”

Before he can do that, with the season still six or so weeks away, Corbin will focus on getting acclimated to the organization. He was with the Diamondbacks for six seasons and it became easy to fall into the rhythm of knowing everyone’s name, every nook and cranny of the clubhouse, every schedule depending on which city the team was traveling to. Now he has to learn that all again — “I’ve been saying hi to a lot of people,” he said this week — with the biggest difference being that everyone else recognizes his face.

That is a another thing that’s changed after all these years. The key, for Corbin, for the Nationals, is that he hasn’t.

Read more on the Nationals:

Carter Kieboom, Nationals’ top prospect, seeks greatness amid a family legacy

Competition or not, Jeremy Hellickson sees himself as Nationals’ fifth starter

Stephen Strasburg’s first spring bullpen session inspires confidence

Boswell: Max Scherzer says baseball’s free agency lull ‘poisons the game.’ He’s right.

Kyle Barraclough doesn’t know his role yet. He’s not alone in the Nationals’ bullpen.

‘The clock is ticking’: Nationals players are also waiting out the Bryce Harper situation