CLEARWATER, Fla. -- Andy Pettitte threw three innings in his first start for the Class A Advanced Tampa Yankees on Monday night, another checkpoint on the 39-year-old lefty's comeback trail.

Pitching against the Clearwater Threshers at Bright House Field, Pettitte gave up two hits (both doubles) and one earned run, striking out two but also throwing a wild pitch. He threw 26 of his 32 pitches for strikes and reported that he felt "really good" about his outing.

"I just know this is a process -- it's going to take a little bit of time," said Pettitte, who could be ready to join the Yankees in May. "Tonight was another good step. My legs felt really good under me. It's another good step in the right direction."

Monday was Pettitte's first outing since he threw a scoreless relief inning in Grapefruit League play last Wednesday. His next step should be a start on Sunday at George M. Steinbrenner Field for Tampa, and he hopes to increase his pitch count to 50 in that start.

Citing his heavy workload since deciding to return from retirement, Pettitte said he plans to take it easy on Tuesday, then get back in his normal routine on Wednesday or Thursday in preparation for his start on Sunday.

"I haven't had a break since I've been down here," Pettitte said. I've been throwing a lot to get ready for this. I've been throwing every other day since I've been down here."

Pettitte needed only eight pitches, all strikes, to work through a perfect first inning. He gave up a leadoff double in the second, struck out his first batter, allowed the runner to advance on a wild pitch and gave up a run on a sacrifice fly. He got out of the inning by fielding a comebacker and tossing it to first base.

Pettitte gave up a fluky double in his final inning, when a grounder down the left-field line took an odd bounce off third base, but the lefty induced a groundout, recorded his second strikeout of the night and ended the inning with a flyout to center.

Pettitte's only concern throughout this process has been building up stamina and leg strength, and he said everything felt fine on that front on Monday. Pettitte said the outing also provided a good opportunity to pitch out of the stretch and work on his slide step.

"This was a short sample, a short outing," Pettitte said, "and I feel like maybe I didn't get a chance to throw some of the pitches that I would like to have thrown and work on some of the sequences that I would have liked, because I was getting guys out early in counts.

"But all in all, I feel real comfortable with everything, so it was another good step."