When Billy Wagner was healthy and popping off on a regular basis, he often joked about retirement. He liked the idea of going out on his terms.

That’s gone now.

Wagner will have surgery to repair a torn MCL in his left elbow, and with recovery time of one year, we’re talking 2010. Wagner has his money, but what remains to be seen is whether he’ll have peace of mine and be willing to leave like this. No athlete wants to leave the game injured.

“That was a scenario that I was not expecting,” general manager Omar Minaya said today.

Wagner walked off the mound during a bullpen session Sunday afternoon. At 37, he has one year and $10.5 million left on the contract signed before the 2006 season.

The Mets hold an $8 million option for 2010, which they likely would not pick up without having seen him pitch next year.

Wagner saved 101 of his 385 career games with the Mets and was a two-time all-star. He lived up to his end of the bargain. Yes, he had blown saves, but nobody quite blew a save like Wagner.

Wagner went on the DL with a strained left forearm, Aug. 5, and the team has gone to a closer-by-committee role. Things were spotty at first, but Luis Ayala settled into the role by converting five of six save opportunities.

“Surgery was always a possibility if things did not get better,” Minaya said. “And we’re at the point right now where things did not get better. … In a lot of ways, you almost got the feeling that we were going to have to do this without Billy. Baseball is not about one guy. It’s about a team, and the concept of togetherness.”