BOSTON -- Red Sox reliever Tyler Thornburg could be in the home stretch of his comeback, as he will begin a Minor League rehab assignment for Triple-A Pawtucket on Monday.
Acquired in a trade with the Brewers to be the eighth-inning setup man for the Red Sox on Dec. 6, 2016, Thornburg missed all of last season with arm troubles and wound up having surgery to repair thoracic outlet syndrome in his right shoulder.
The right-hander could be a big piece for the Red Sox when he returns. Don't be surprised if the Red Sox give him the full 30 days he is afforded on his rehab assignment.
"Kind of Spring Training for him, obviously," said Red Sox manager Alex Cora. "It's a process. Obviously [we'll] want him to go back to back, it's a longer process, but the fact that he's going to be pitching tomorrow, that's great -- great for him obviously. Going into Spring Training, everyone knew his situation, and for him to grind it out and to put himself in this spot is awesome. Obviously for us, it's great. It's going to be a great day for him and the organization."
Pitchers have had varying success coming back from the thoracic outlet syndrome, but Thornburg has provided some encouraging signs.
"He's throwing the ball well, his velocity is up, the offspeed pitches are a work in progress, but I think challenging him at that level will be good for him," said Cora. "He has to pitch. I think facing higher levels for him is going to be a challenge, and he's up to it."
Once Thornburg returns, he will join a righty setup crew that includes Joe Kelly (currently serving a six-game suspension), Matt Barnes and Richard Hembree.
Pedroia getting extended
Second baseman Dustin Pedroia is starting to play extended spring training games in Fort Myers, Fla. as he continues his comeback from a cartilage restoration procedure on his left knee.
"He played three innings on Friday, one at-bat, actually had a conversation with him yesterday as a group with [trainer] Brad [Pearson], myself, Tim Hyers, and you guys know Dustin, he wants to play, let's be honest," said Cora. "He feels great. I joke around with you guys about the videos and all that, but in all seriousness he's sending videos to show me how much better he looks. And he looks better.
"You guys saw him taking ground balls, he's more explosive. But it's a process. He hasn't played in a while, it was a major surgery, and when he comes back I want to make sure he's back."

Mookie still day to day
Right fielder Mookie Betts was out of the lineup on Sunday, one day after he exited in the fifth inning with tightness in his right hamstring.
"He's better. He's day to day," said Cora. "I don't want to say I want to stay away from him, but I do want to say I want to stay away from him, for obvious reasons. If this game is September, October, November, I guarantee he'd play, but we have to take care of him. He felt it early in the game."
Xander Bogaerts was also out of the lineup as planned for maintenance in his third day back from the disabled list.