Manager Joe Girardi made the announcement after Friday night's 5-3 exhibition loss to the Florida Marlins in Miami, while adding the 35-year-old left-hander showed no ill effects from his recent back trouble in a bullpen session Friday.
Pettitte is scheduled to make a start in a minor league contest in Tampa Sunday and will be re-evaluated by team doctors after his outing.
Girardi said he expects Pettitte to be ready to pitch against the Tampa Bay Rays next Saturday.
"Everything's great," Girardi said on the Yankees' Web site. "It puts him on schedule to be in the first rotation."
Pettitte, who enters his 13th major league season, has been slowed all spring by nagging back spasms.