A.J. Burnett threw a nifty little changeup, walked off the mound at McKechnie Field and raised his arms in celebration.

By throwing a 40-pitch session of batting practice Saturday morning, Burnett took another step toward joining the Pirates' starting rotation.

"A big step," Burnett said. "I wanted to open some eyes today, so, hopefully, they'll see that I'm a little bit more ready than they thought. It was a good step in the right direction."

The right-hander is expected to be out until at least early June after having surgery to repair a fractured right orbital bone. After yesterday's workout, Burnett repeated that he intends to stick to a cautious timetable.

"It's all in pencil, though," Burnett said with a wink.

It was the third time Burnett has thrown off a mound and marked his debut against batters. He worked from behind a L-shaped screen, facing right-handed hitter Michael McKenry and lefty Garrett Jones. Burnett threw fastballs to both sides of the plate, crisp curves and changeups.

"He had great arm action, nice and loose," McKenry said. "The ball was coming out of his hand real well. I think he looks game-ready, to be honest. He looks pretty sharp."