TORONTO -- As Red Sox right-hander Brad Penny faces the archrival Yankees on Friday, two of Boston's rehabbing pitchers will also take the mound: Knuckleballer Tim Wakefield will pitch for Triple-A Pawtucket, and Daisuke Matsuzaka is scheduled to throw a side session.
Wakefield, who was originally shelved with a back injury and has since dealt with weakness in his left calf related to the back issue, will likely throw around 75-80 pitches in Pawtucket, Red Sox manager Terry Francona said on Wednesday.
Both Wakefield and the Red Sox were concerned that pitching could worsen his injury, but the team's medical staff put those fears to rest.
"He's not endangering himself by pitching," Francona said. "He's cleared to pitch as tolerated. Wake was satisfied and reassured by the call, which I think is good.
"He's got a disc fragment [in his back] -- we know that -- and it's created some nerve damage that's gone to his calf, and so he's lost some strength there and that's what he's dealing with. He's not endangering his potential recovery of leg strength by waiting until October if -- if -- a surgical procedure to take that fragment out is needed.
"And again, these are big ifs."
Francona said Wakefield was able to pitch, but worried that landing on his calf 75 or 80 times in a game -- plus fielding the ball -- could cause problems, hence the decision to send the knuckleballer to Triple-A rather than putting him back in Boston's rotation.
"If things don't go well [in Triple-A], we always can take him out of a game," Francona said. "And if they do go well, then we can bring him back and pitch for us. So that's kind of where we're at."
Matsuzaka, meanwhile, appears to have a slightly longer road to recovery. The right-hander struggled in eight starts this season, posting an ERA of 8.23, and he is now on the 60-day disabled list with a right shoulder strain.
Francona said that after Matsuzaka's side session on Friday, he will pitch in the Gulf Coast League on Monday, before returning to Boston for a reevaluation by the team's medical staff.
Matsuzaka will then make two starts for Double-A Portland, likely throwing around 50 pitches, before making a start for Triple-A Pawtucket if everything goes according to plan, Francona said.
Francona added that he hoped Matsuzaka would throw "65ish" pitches for Pawtucket.
"I add 'ish' to the end of it because we'll see," Francona said. "He's doing great."
Erika Gilbert is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.