"Jake Peavy likely will miss at least one start, but the White Sox haven't put the right-hander on the 15-day disabled list.

Peavy was diagnosed Monday with a mild strain of the right groin after undergoing an MRI at Rush University Medical Center. Peavy, who pitched four innings Sunday, returned to U.S. Cellular Field for more treatment.

Manager Ozzie Guillen wasn't upset after Peavy — who needed 10 months to recover from a detached latissimus dorsi muscle near his right shoulder — revealed Sunday that he first felt discomfort in his groin after a May 30 start in Boston.

"This guy wants to be out there, this guy wants to help us," Guillen said. "Besides, we're in the fourth inning, and we were very short in our bullpen."

Guillen said Peavy never asked for more time between starts to let the discomfort subside, adding he already had five days to recover."