The veteran left-hander pitched four scoreless innings in his second Minor League start Sunday afternoon as he works his way back to the Bronx.
"Obviously, you know at this stage for me, any setback would cost you a month, maybe, or so," Pettitte told MLB.com after allowing a pair of singles and striking out three in Class A Advanced Tampa's 6-1 victory over the Clearwater Threshers.
"I'm just happy that I'm progressing the way I am. I don't want to start talking too much about how great I feel or whatever. I just want to get back up there, get ready and get back up there with the guys and start going to battle with them."
Pettitte used his trademark sinker to record seven ground-ball outs. The Threshers hit just one ball in the air, a popup by Jeremy Barnes that was fielded in shallow right field by second baseman Kelvin Castro.
The 39-year-old southpaw fanned two in a 16-pitch first inning, then needed only 14 combined pitches to get through the next two frames. Carlos Alonso and Brandon Tripp singled with one out in the fourth, but Pettitte ended his day by getting Jim Murphy to hit a comebacker that the three-time All-Star turned into a double play.
"Everything feels pretty good," Pettitte said. "Unless every pitch is perfect, I kind of get frustrated with that. I felt like I cut a couple pitches off and, of course, you know at the big league level when you do that and balls come back over the plate, that could cost you a little more than it could down here."
In his season debut on April 9, also against Clearwater, Pettitte yielded a run on two hits over three innings. Projected to return to New York next month, he said he expects to make some starts for Double-A Trenton.
A five-time World Series champion as part of the Yankees' "Core Four," Pettitte announced his retirement following the 2010 season. He signed a Minor League contract in March and made one appearance in a Spring Training game before joining Tampa.
Tampa manager Luis Sojo, who was Pettitte's Major League teammate from 1996-'99 and 2000-'03, told MLB.com he looks like the "same guy."
"For a guy who hasn't pitched in a year, that's very impressive," Sojo said. "He's throwing strikes. Every pitch has worked. He's been confident. I would be surprised if that was somebody else. Andy is a very dedicated guy. He's very professional and he wants to come back for a reason. The reason is that he's feeling good."
Pettitte exited with the Yankees leading, 1-0. Clearwater tied it in the fifth on Edgar Duran's two-out RBI single, but Tampa's Neil Medchill answered with a solo homer in the sixth and Jose Mojica delivered a two-RBI single in a four-run eighth.