WEST PALM BEACH, Fla. -- Starting left-hander Jon Lester is flying to New York on Wednesday to undergo a procedure to remove his thyroid gland on Friday, manager Dave Martinez said prior to the Nationals' game against the Marlins.

The Nationals signed Lester, 37, to a one-year contract in January as their fourth starter. Martinez said the Nationals had been aware of the condition and were awaiting test results. After consulting with a doctor on Tuesday, Lester made the decision to have the gland removed during Spring Training.

“He said he felt kind of tired, that’s the big issue,” Martinez said on Wednesday morning. “I feel like once they get this out, he’ll have a lot more energy throughout the day. I hope it works out for him. I really do. He’s a big part of what we do here, and we love having him.”

Lester was diagnosed with anaplastic large-cell lymphoma (a form of non-Hodgkin's lymphoma) in 2006 during his rookie season with the Red Sox. He underwent chemotherapy and returned 11 months later.

“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. “I think he’s upbeat about it -- I know he’s upbeat about it. 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.”

Lester had been slated to make his first Grapefruit League start on Thursday against the Mets. (Kyle Finnegan will get the nod in his place.) Martinez expects Lester could resume pitching in a week after the procedure. Lester arrived at camp ramped up with a few bullpens under his belt, and Martinez said the plan still is for Lester to make his first start of the regular season as scheduled.

“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.”

A three-time World Series champion and five-time All-Star, Lester is 193-111 with a 3.60 ERA over his 15-year career. Last season, he pitched to a 3-3 record and 5.16 ERA with the Cubs.

“From what I'm hearing, it's not very serious,” Cubs manager David Ross told Cubs media members on Zoom on Wednesday. “I don't think he's going to be out very long. But, I don't want to comment on somebody else's medical conditions. But, yeah, definitely all the best to Jon and we'll say a prayer for him. I think he's not worried, so that makes me not worry.”