© 2009 MLB Advanced Media, L.P. All rights reserved.

08/08/09 8:07 PM ET

Peavy to start for Charlotte on Thursday

Successful sessions keeping Aug. 28 debut on target

CHICAGO -- Jake Peavy threw off the U.S. Cellular Field mound with hitters in the batter's box during Saturday's bullpen session, his third sideline in testing the strained tendon in his right ankle that has put him out of action since June 8.

The right-hander has one more bullpen scheduled for Monday in Charlotte, and then will start for the White Sox Triple-A affiliate on Thursday night. If Peavy goes through three injury rehab starts, a desire previously expressed by pitching coach Don Cooper, then he should be ready to start for the White Sox by Aug. 28 at Yankee Stadium.

His return date remains flexible.

"[August] 13th, 18th, 23rd, 28th, [September] 3rd," Cooper said. "Those are the dates he's scheduled to go, and we'll use as much as we need to decide, along with him, when he's ready to make his Chicago White Sox debut.

"We're off and running right now. We're not going to make a mistake with this. We're not going to rush with this. When he's ready, he'll be out there. Right now, it looks like late this month is a date that we might be able to do it, but it's not etched in stone."

Saturday's effort consisted of 52 pitches over three mock innings, during which Peavy threw all of his pitches and worked from both the windup and the stretch. He also went through all the defensive drills for a pitcher. Peavy believes the session was another positive step, reporting absolutely no ankle pain, but doesn't want to pencil in his White Sox debut before he continues to build back his game with Charlotte.

"I've got a long way to go getting my legs back strong," Peavy said. "That's the biggest thing is getting my legs under me and getting my arm strength back.

"Your legs are your power. You throw a ball 94 mph, you're going to use your legs and arms and your torso as well. For the longest time, a six- to eight-week period, I was able to not do anything. So I'm just still trying to get my strength back to be who I want to be and have the velocity and the stamina that I know I want to have."

White Sox general manager Ken Williams said that Peavy's on-field results for the Knights won't make the slightest difference in the decision to bring him to the White Sox. He's going to follow Peavy's directive as to how he feels, which could mean anywhere from two to four rehab starts.

With this American League Central race figuring to go down to the final days of the season, adding a second ace to the staff at 100 percent health should benefit the entire rotation.

"You can have all the stuff you want, but it takes a little something extra to become a No. 1 and No 2," Williams said. "They can be just assets with their knowledge and the way they go about their business."

"I've got to build the pitch count up, build my endurance, arm strength, and sharpness," Peavy said. "When all that comes together, I'll make a start here. But everything is tentative as of now."

Scott Merkin is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.