ST. PETERSBURG -- The Red Sox still have Junichi Tazawa listed as their probable pitcher for Saturday afternoon in Chicago. However, it might not be a stretch to say that it is also probable that Tim Wakefield will be inserted into that spot within the next 24 hours.

The veteran knuckleballer, who has dealt with back woes throughout the second half, gave it a test run on Thursday, throwing a 25-pitch side session at Tropicana Field.

Will Wakefield pitch on Saturday?

"I hope so," said Wakefield.

Is he ready?

"Yes," Wakefield said. "It's not up to me to decide that though. It's up to them. My pain is what it is."

According to manager Terry Francona and pitching coach John Farrell, the Red Sox simply want to make sure the 43-year-old Wakefield has no lingering effects from his side session before putting him back into the rotation.

"Now we'll certainly see how he recovers from it and make a decision," Francona said. "We don't really have to [now]. We have Saturday's game, it could be Tazawa who we have lined up right now. We'll see. We'll just see how it goes. We want to sit down with Wake, later today and tomorrow and see how he feels. We've already talked to [general manager] Theo [Epstein] a little bit about it, and John Farrell. We'll just kind of see how it goes."

Will the Red Sox be looking for anything specifically from Wakefield on Friday before putting him into Saturday's slot?

"I just think to make sure he shows up and he's not hurting," Francona said. "He's able to execute all his pitches really well. That's not the issue. If he shows up and all of a sudden he's limping or more sore than he was, that's probably not a real good situation to put him in."

Wakefield was asked if he was moving around any better on Thursday than in recent weeks.

"It's the same as it's been for the last two and a half months," Wakefield said. "The pain has gone away -- the pain from after my last start. So that's a good sign."

Wakefield made an encouraging return to the active roster on Aug. 26, throwing seven innings of one-run ball against the White Sox. But two days later, his back had completely locked up on him again, and he hasn't pitched since. Wakefield received a cortisone shot on Monday.

That shot has already provided relief. Wakefield hopes he staves off a recurrence of the spasms for as long as possible.

"Who knows?" said Wakefield. "I'm going to push it until I can't go anymore and then make a decision after that."

Wakefield will eventually need surgery to remove the loose fragment from his back that is causing the discomfort. The recovery time is only expected to be about a month.

"I'm ready to go back," said Wakefield. "I was a little doubtful after my last start when I had that pain, but after the injection, everything feels a lot better. We'll see how I feel tomorrow. It's more or less day to day."

Farrell liked what he saw on Thursday.

"The execution of pitches and the quality of the knuckleball that he was able to throw was there today throughout the entire session, so he's doing everything that he's capable of at this point," Farrell said.