A MRI performed after a bullpen session Tuesday revealed that Pettitte has a small, persistent strain, explaining why he is still experiencing discomfort when the intensity of his pitches increases. Pettitte can still play catch, but that is about all for now.
"I thought I was a week ahead of schedule, maybe," Pettitte said. "[Tuesday], I felt unbelievable. I felt great. I tried to turn the intensity up like I would if I was going to face a hitter. ... It's just not allowing me to push when I want to go real hard, and I'm getting some irritation in there."
Pettitte suffered the injury in a July 18 start against the Rays and believed there was "no doubt" he would be back to pitch in the Aug. 6-9 series against the Red Sox, or the Aug. 12-15 Royals series at the latest.
Obviously, both predictions fell flat, and Pettitte now figures that his best-case scenario might be about three weeks from this point, which might have him big league-ready to pitch in the Sept. 10-12 series at Texas.
"I'm trying now to not figure this out and plan it out the way I always do," Pettitte said. "I'm just trying to take it day by day and figure out exactly what to do."
Yankees manager Joe Girardi said that he expects Pettitte will need two Minor League rehab starts to return to the team, and targeted the third week of September as a point when it would begin to become a concern if Pettitte would be ready to start a potential postseason game.
"The last thing you would want is for him to come back and say, 'I feel that I can only give you 60 pitches and I don't think my stuff is crisp,'" Girardi said. "That's not really going to help us.
"Until he goes out on a rehab start, to me, he's not where we need him to be. We talked about five weeks, and now we're beyond five weeks. Groins are very tricky for pitchers, especially when it's that push-off leg."