Al Horford is in an exclusive club. It’s just not a group to which one wants to belong.

The Hawks center spoke publicly for the first time Thursday following his season-ending surgery to repair a torn right pectoral muscle in December. It is his second experience with the injury after he missed most of the 2011-12 season with a torn left pectoral muscle.

“It’s the third one to happen in basketball, and I’ve had two of them,” Horford said.

For the record, the Grizzlies’ Darrell Arthur also suffered a torn pectoral muscle during the 2009-10 season. Horford said doctors told him that he was not predisposed to such an injury.

Horford returned from his first torn pectoral muscle in time for the playoffs. That is unlikely this season. He said this injury was more severe.

“It’s my right side and my shooting arm,” Horford said. “I need to feel 100 percent confident with it. It’s just going to be a little bit slower.”

Horford was injured Dec. 26 in a game against the Cavaliers. He had season-ending surgery Dec. 31 performed by Dr. Xavier Duralde, who diagnosed the complete tear. Horford said he didn’t immediately realize the extent of the injury.

“I didn’t,” Horford said. “No. I was trying to be positive about the situation. I was actually thinking about going back in the game. I was on the bench (saying) ‘No, no, I’m OK.’ Then there was something wrong.

“They took me back (to the locker room), and the Cleveland doctor came to take a look at me. I went to lay on the table, and something there popped. … I screamed. It hurt pretty bad. I just saw his face. … I didn’t even take my shirt off. His face was priceless. Then I knew it wasn’t looking good.”

Horford said that during the surgery Duralde noticed scar tissue, an indication that there had been a previous issue with the muscle.

Horford was upbeat during his interview with the media. He smiled and laughed when speaking of the incident and his rehabilitation, signs that he has come to grips with the lost season.

“It’s one of those things that it happened and you can either let it get you down or you can look forward and start focusing on the next thing,” Horford said. “For me, this is a setback. It’s a small challenge. But I welcome it. It is something that I have experienced before. I can do it. I know I can. I’m working on it.”

Horford has rehabilitation exercises, mostly cardio work. He also is working on conditioning in his legs, abdominal muscles and back. He said he has been around the team recently, but has stayed behind the scenes.