The White Sox confirmed earlier reports on Tuesday that Peavy will make his White Sox debut against the Kansas City Royals on Saturday.
Peavy, who started the year with the San Diego Padres, suffered a right ankle injury in June and has been on the disabled list ever since. He was getting close to a return a few weeks ago but took a line drive off his pitching elbow in a rehabilitation start, pushing back his Sox debut.
"I don't expect to be 100 percent," said Peavy, who was 6-6 with a 3.97 ERA in San Diego. "I'm not. I'm excited about getting out there and competing."
In four starts with Triple-A Charlotte, Peavy was 1-1 with a 2.93 ERA.
"This is what we've been looking for for a long time," White Sox manager Ozzie Guillen said. "Since he got hit with the ball, it's been two [more] weeks since he was supposed to be on the mound. It's going to be interesting. I think it will be exciting."
Information from The Associated Press was used in this report.