Andy Pettitte received good news from his Monday X-ray and will begin long-tossing this week, but previous setbacks put enough fear in the 40-year-old that he will take a cautious approach to his recovery from a fractured left ankle.

"I know that now if I have another setback, we've got serious problems and my season's probably over," Pettitte said. "Now we're probably going to be overcautious about what we can do to make sure I'm back."

Pettitte planned to travel on the Yankees' most recent road trip to Detroit and Toronto to begin long-tossing then, but an X-ray taken before the team's departure did not convince doctors that the left-hander would be able to put the strain on the ankle, which was fractured on a June 27 comebacker.

He previously traveled with the team to Seattle and pushed himself too much, which created swelling that stunted the healing process, made it difficult to walk, and cost him an estimated 10 days in his rehab.

"You have to watch Andy every step of the way," said manager Joe Girardi. "He thought it was going to heal in two weeks and he was going to be back on the mound in four, but that's just Andy. That's the competitive nature in him, so you have to watch what he does to make sure he doesn't do too much."