TAMPA, Fla. (AP) – Yankees left-hander Andy Pettitte threw 31 pitches Wednesday during his second bullpen session since experiencing back spasms earlier this month.

Pettitte is scheduled to pitch in a minor league or simulated game Friday.

“Depending on tomorrow, which we always say for safety sake, and make sure he comes out of this,” Yankees manager Joe Torre said. “That will be another test for him.”

Torre expects Pettitte to break camp with the team, although his first start of the regular season may be pushed back a few days.

“I think today was a big step, leading us to believe, let’s put it this way, we’ll leave Florida with him,” Torre said. “Which is something we weren’t sure about a week ago.” Pettitte said he felt fine and is looking forward to his first game action since being hurt on March 19.

“Just to see batters, it’s important,” Pettitte said.

Right-hander Jeff Karstens will resume throwing Thursday. He has been shut down since leaving his start last Sunday after two innings with right elbow stiffness.

It is possible Karstens might not need to start the season on the disabled list.

Torre still hasn’t announced his opening-day starter for April 2 against Tampa Bay. Carl Pavano is considered the frontrunner.

“I’m comfortable watching him,” Torre said. “He’s back as far as one of the guys that can go out there and compete on a regular basis. He’s determined to be one of the guys.”

Pavano hasn’t pitched in the majors since June 2005 due to a variety of injuries.

Mike Mussina will pitch in a minor league game Friday. Torre said it’s likely the right-hander will face the Devil Rays in the second game of the season Wednesday.

Japanese left-hander Kei Igawa remains scheduled to start Saturday’s spring training finale with Detroit.

AP-ES-03-28-07 2005EDT