The left-handed starter had been resting his fractured fibula at his home in Deer Park, Texas, since he suffered the injury on June 27.
"I'm antsy. You want to work," Pettitte said. "If you're not able to pitch, you at least want to go out, go for a run, get a good sweat going, because you're used to that. But patience right now is what I'm doing -- doing what I can to stay in shape."
Pettitte played catch with pitching coach Larry Rothschild on Friday, throwing curveballs and cutters off the flat ground in the Yankee Stadium outfield. He was hoping to get an X-ray on his ankle Friday, but the training staff postponed the checkup until Sunday.
While he is still far from throwing off a mound because the injury is on his push-off foot, Pettitte did pick up the intensity in his session on Friday from the few times he played catch with his kids at home.
The target date for Pettitte's return remains around Sept. 1, six weeks after a ball caromed off his leg during a game against the Indians.
"No matter what the X-rays really look like, it takes six weeks," Pettitte said. "So I'm counting the days for six weeks, from the Wednesday when I hurt it. Six weeks from there, I'm hoping to be standing on a mound throwing a [bullpen session]."
Pettitte has played light catch every other day since the injury in order to keep his arm loose. At the beginning, that required the use of a pair of chairs, so the 37-year-old could sit in one while resting his left leg on the other. Now that the trainers wrapped up Pettitte's leg, he has more stability, making it easier for him throw from a standing position.
"It's amazing when you hurt your foot, your ankle, whatever, how much leverage you use with your feet to throw," Pettitte said. "I was concerned with the back of my shoulder maybe getting a little achy."
Pettitte will stay with the team in New York for the foreseeable future, and he hopes he can hit the road with the team to work with the trainers and offer advice to members of the Yankees' pitching staff.
"Obviously I feel like I'm extremely close with the guys on this staff," Pettitte said. "I just hope while I'm out, [I'll do] whatever I can do, talking with somebody or somebody bouncing stuff off me before the game or during the game, whatever. That's what, obviously, I love to do."
Despite his recent setback, Pettitte said he never had second thoughts about returning to play this season.
"I've got to come back from this," Pettitte said. "I never really thought [about not coming back] at all."
Ethan Asofsky is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.