FORT MYERS, Fla. -- Right-hander Tyler Thornburg had just unleashed the 20th and final pitch of his first full side session since undergoing surgery, and catcher Christian Vazquez let out an audible, "Whoooooo".Red Sox manager Alex Cora came over and gave the reliever a hug.• Spring Training: Info | Tickets
FORT MYERS, Fla. -- Right-hander Tyler Thornburg had just unleashed the 20th and final pitch of his first full side session since undergoing surgery, and catcher Christian Vazquez let out an audible, "Whoooooo".
Red Sox manager Alex Cora came over and gave the reliever a hug.
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Thornburg was excited and relieved. Best of all, he was not tired or sore. He wanted to keep pitching.
Wednesday's step was a significant one as Thornburg makes his comeback from thoracic outlet syndrome surgery on his right shoulder.
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"Pretty darn good," was the way Thornburg described the feeling of being back on the mound. "It's one of those feelings you realize you miss a lot once you don't do it for a year, I guess."
Now, Thornburg will get on a steady progression that will eventually lead him back to the Red Sox, though it's too soon to know when that will be.
"I felt like I could have thrown more which is probably one of the better feelings you can have afterward," Thornburg said. "Now it's pretty much just do what we can. Always want to push it, but try to stay with a relatively normal progression."
If Thornburg is added to a solid righty setup crew of Carson Smith, Joe Kelly and Matt Barnes, the bridge to elite closer Craig Kimbrel would be a sturdy one.
This would mean that Thornburg would be one of the pitchers who did have success coming off the thoracic outlet procedure, which hasn't been easy for everyone. Just ask Matt Harvey.
But it has worked for others. Aaron Cook was an All-Star after having the procedure. Josh Beckett fired a no-hitter for the Dodgers the season after he had it done.
The thoracic outlet condition occurs when the nerves and/or blood vessels between the collarbone and the first rib become compressed.
Due to the condition, Thornburg didn't pitch at all last season, his first with the Red Sox. In 2016, he was one of the best setup relievers in the game for the Brewers, when he posted a 2.15 ERA and notched 90 strikeouts in 67 innings. But Thornburg admitted on Wednesday that the thoracic outlet symptoms were already bothering him then, making him optimistic about how well he can perform without that discomfort.
Thornburg admits it was stressful in the days leading up to the surgery he had on June 16, 2017.
"Very nerve-wracking just because I was following all those guys," Thornburg said. "I've had symptoms for a couple of years now and watching Matt Harvey and Tyson Ross and all those guys not necessarily have success and me going under the knife to do that, it's pretty scary. But there's different types of it. There's different levels of it.
"I know it was something where I felt confident, because the surgeon said that he knows 100 percent that's what it was and it made me feel a lot more confident after."
Cora didn't know what to expect before Spring Training. But the first time he saw Thornburg playing catch, he sensed he could make it back.
"He was playing catch with conviction," Cora said. "I talk to him every day. He's an honest kid, he'll let you know and he actually likes the soreness, being sore in the right places. He's had a lot of those days here in camp which is good. He's one of the first ones always at breakfast and I'm always able to catch up with him. He feels great about it. We all are pushing for him, we know how good he can be. With the conviction he's throwing the ball, it's not going to surprise me that he'll contribute this year with us.
"Everybody is different. There's guys who have come from it and been successful. Others have failed. I feel like with the way we're working and the work he's put in, everything is trending that he's going to be fine and he's going to be back and he's going to perform."
Thornburg has potential return dates in his mind, but he will make sure not to let that be detrimental to the process.
"All the time. Any competitor does, really," Thornburg said. "I'd be lying if I said to you, 'No, that's down the road.' I look at the calendar a lot. But at the same time, in my head, it's like, maybe I can do this, but at the same time, is it smart to push it there? Right now, I really don't know because I could bounce back from every bullpen and every live BP, and every game better than I did before, and it could move a lot quicker than expected.
"And it could also be the other way around. There are new muscles working so they could get ultra-sore. But how I feel right now is a pretty good feeling as far as looking forward to a bullpen again in a couple of days."
Ian Browne has covered the Red Sox for MLB.com since 2002. Follow him on Twitter @IanMBrowne and Facebook.