"You kind of rely on the doctors here, and the doctor was extremely positive about the results of what he found when he did the operation, and the relief that he gave Matt," Boras said. "It was really just a nerve compression. He didn't have sensation [in his fingers]. And so clearly, the procedure allowed that relief where the nerve is now free and he should have full feeling in his hand.
"This is not like a Tommy John, where you have a ligament issue. It's really about relief of nerve compression. So you get a little bit more of a higher probability rate on those kinds of things."
After going 4-10 with a 4.86 ERA in 17 starts this season, struggling to find his usual command, Harvey underwent surgery on July 18 to remove a rib. The goal was to free compressed nerves traveling from his shoulder to his armpit, allowing them to function normally again. For much of this season, Harvey was pitching without complete feeling in his arm and fingers.
"When you lose that sensation, man, it's scary for a pitcher," Boras said. "You don't know. He's sitting here struggling and he's struggling and he's struggling, and it's so mentally stressful not to be able to execute."
Once Dr. Robert Thompson performed the operation in St. Louis, Boras said, Harvey immediately felt "big relief." (The Mets have not made Harvey, who is 29-28 with a 2.94 ERA over a four-year career in New York, available for interviews in the three months since his surgery.)
Around this time next month, Harvey will report to Boras' training center in Newport Beach, Calif., where he has spent past offseasons. There, he will work on full-body conditioning while continuing his rehab from surgery. The goal is to report to Port St. Lucie, Fla., in early February in normal Spring Training shape.
"He should be fine," Boras said.
But until Harvey pitches in a big league game for the first time since July 4, doubts will linger. A significant percentage of pitchers who have undergone surgery to correct thoracic outlet syndrome in recent years, including Josh Beckett and Chris Carpenter, did so near the ends of their careers. The most prominent and successful example is Chris Young, a soft thrower who has gone 26-24 with a 4.06 ERA in three seasons since his operation.
Despite the lack of precedent, Boras believes Harvey, who missed the entire 2014 season following Tommy John surgery, will rapidly return to full strength.
"The doctor was very clear," Boras said. "The doctor's certainty is that he was able to give a nerve space so it could function normally."