WEST PALM BEACH, Fla. — Washington Nationals starter Jon Lester left the team to undergo thyroid surgery in New York, Manager Dave Martinez said Wednesday. The procedure is scheduled for Friday, according to a team spokesman, and will remove Lester’s thyroid after the left-hander felt fatigued during spring training workouts. Martinez said, health permitting, Lester could be back on a mound in the near future.

“If everything goes well, he’ll be back, hopefully he can pitch again in about a week,” Martinez said on a video call with reporters. “We want him to get it taken care of now, so it’s not an issue.”

He continued: “We’ve known he’s had it. We were waiting for some other results to come through. Talked to the doctor [Tuesday], and he wants to go ahead and have it removed, which we all agree was a good thing for him. He’ll feel better with that gone. And then we’ll go from there.”

Lester could return in five to seven days after the surgery, Martinez explained based on his conversations with team medical staff. Lester will have to repeat mandatory coronavirus intake screening upon returning to West Palm Beach. The 37-year-old signed a one-year, $5 million contract with the Nationals in January. He has made at least 31 starts in every full season since 2008. His durability and health are defining strengths.

But his major league career began with a battle against anaplastic large cell lymphoma as a rookie with the Boston Red Sox. The cancer was diagnosed in September 2006, and after offseason chemotherapy treatment, Lester was in remission by December. When asked Wednesday whether Lester’s medical history made this thyroid issue more concerning, Martinez did not go into specifics. Lester, who spent the past six years with the Chicago Cubs, didn’t speak with reporters before he left for New York.

“I definitely believe in talking to him that it’s something that for his mind’s sake that we needed to take care of right away,” Martinez said. “He’s upbeat about it. I know he’s upbeat about it. So as soon as we can take care of that, all he wants to do is come back and help us win and get back on the mound. So we’re all for it.”

Cubs Manager David Ross told reporters in Arizona: “From what I’m hearing, it’s not very serious. I don’t think he’s going to be out very long. … We’ll say a prayer for him. I think he’s not worried, so that makes me not worry.”

Lester was originally scheduled to make his spring debut against the New York Mets on Thursday. Upon signing this winter, after a World Series win and two all-star appearances in Chicago, he was immediately penciled in as the Nationals’ fourth starter. Washington targeted him in free agency because he’s reliable.

Each year, he stays on an every-fifth-day schedule that teams crave. And in most starts, he is good for at least five innings. Lester dipped in 2020 with a 5.16 ERA in 61 innings. As recently as this week, the Nationals were banking on him improving those numbers while maintaining that steady workload.

“I project a veteran presence who is going to be very, very helpful, a great clubhouse guy,” said new pitching coach Jim Hickey, who briefly overlapped with Lester in Chicago. “But also someone who’s going to take the ball . . . I’ll say the words: every fifth day. . . . He’s going to give you innings. He’s going to compete. He’s going to throw the ball over the plate.”

The main priority is Lester’s short- and long-term health. Well below that, though, is what this means for Washington’s rotation to start the season. Lester was signed to pitch behind Max Scherzer, Stephen Strasburg and Patrick Corbin. After that, the club is again looking at Joe Ross, Erick Fedde and Austin Voth to round out the staff.

Ross is the supposed front-runner. One of the odd men out probably will join the bullpen as a long reliever. But Lester’s absence could bump Fedde or Voth up the pecking order. Like all teams, the Nationals are navigating how to prep pitchers after such an odd year. They ramped up last spring, were shut down for four months, ramped up again in July — that time on a compressed schedule — then had to recover from about a third of their usual innings.

“I’ve actually thrown a few more [bullpen sessions] than I have in the past to this point,” Lester told reporters Jan. 27, just a week after he landed with the Nationals. “Usually I kind of wait until the week before spring training to get on the mound. But there are some things I popped up last year that I needed to work on, I needed to fix, so I got on there a little bit sooner. I’m excited about that. I feel like I’m in a good place physically.”

Even before Lester left camp, Martinez had floated using a six-man rotation come April. A nine-man bullpen is on the table, too. On Tuesday, in a video call with reporters, Hickey predicted the Nationals would need eight starters to account for any missed starts from the top five.

These are the ripple effects of MLB’s first pandemic season. Beyond Ross, Fedde and Voth, the Nationals have rotation depth in Rogelio Armenteros and Ben Braymer. Seth Romero, another starter on the 40-man roster, has just three major league appearances out of the bullpen. It thins out pretty quickly.

Martinez believes Lester wouldn’t face a total reset in the coming weeks. But that will of course depend on how the surgery and next steps go.

“He’s been working his tail off, day in and day out, and I know he’s going to help us,” Martinez said. “So hopefully we can get this done, nip it in the bud and move on and he’s back with us and in action soon.”