By Keith Idec

Robert Guerrero can only hope his return from a 15-month layoff goes as well as the Oakland A’s comeback against the Yankees on Sunday, when Guerrero’s surgically repaired left shoulder looked strong as he threw out the ceremonial first pitch at the Oakland-Alameda County Coliseum.

Guerrero acknowledges his fight against Selcuk Aydin will be anything but easy, but the former featherweight, super featherweight and lightweight title-holder is confident his shoulder won’t hinder him in any way Saturday night at HP Pavilion in San Jose, Calif. In fact, surgery to repair a torn rotator cuff and nearly four months of intense physical therapy have made his shoulder stronger than it was before he suffered the tear while training for an ill-fated fight against Marcos Maidana last summer.

“I couldn’t be happier with the way it came out,” Guerrero said about his injury as he heads into a fight with Aydin (Showtime; 10 p.m. EDT/PDT). “The arm feels good. I’m doing things with it I’ve never done before in all of my boxing career. … I already put that injury behind me and moved on. And I’m in great shape and I can’t wait to get out there.”

The 28-year-old Guerrero (29-1-1, 18 KOs, 2 NC), of Gilroy, Calif., hasn’t fought since he out-pointed Michael Katsidis in an April 2011 lightweight title fight in Las Vegas. He is less concerned about his long layoff because he has felt no ill effects from the Aug. 31 surgery since he returned to the gym without limitations early this year.

“As soon as I was able to start working bags and everything, I went full force,” Guerrero said. “The one thing with the physical therapist that we worked on was letting go, not compensating, not letting your subconscious take over and start compensating for other muscles. That’s what we worked on.

“Throughout my whole career, my other muscles were compensating for the rotator [cuff]. We worked that all out in physical therapy and it’s great. When I was able to get back into the gym and start throwing the left hand, I was throwing it full force and all the way through.”

An encouraged Guerrero even thinks his repaired shoulder will enable him to punch harder. That’s a positive sign because the southpaw will need any advantage he can get while moving up two weight classes to face an undefeated, heavy-handed opponent in Turkey’s Aydin (23-0, 17 KOs).

“There’s a lot more pop in it,” Guerrero said, alluding to his left hand. “Like I said, I’m doing things I’ve never done before. It feels great. Like I said, muscles were compensating for other muscles. When that’s happening, you’re not throwing right. Now I’ve got everything working together in a solid package and I’ve been throwing a lot of strong left hands, and it’s way stronger than it was before.”

Keith Idec covers boxing for The Record and Herald News, of Woodland Park, N.J., and BoxingScene.com.