Newsday’s David Lennon reports that Braden Looper — relieved of his closing duties by the Mets —- is facing shoulder surgery that could well have taken place last spring.

Looper has been bothered by a damaged AC joint in his right shoulder since the end of last season, and chose to forgo the relatively minor operation because he didn’t want to miss the start of this year. Given the ragged state of the bullpen, the Mets figured they couldn’t afford to lose Looper early on, but the decision caught up to them when he imploded in the past month.

Looper converted 28 of 36 chances overall, but suffered blown saves in his last three opportunities before manager Willie Randolph demoted him for Roberto Hernandez and Aaron Heilman. Looper never let on that his shoulder was hurting, and neither did the Mets, until he admitted yesterday that he was scheduled for an MRI today and likely would have the operation done by team orthopedist David Altchek on Monday.

“We knew sometimes he felt discomfort,” Omar Minaya said. “But he always asked for the ball. I think that this late in the year, most guys are a little banged up. There were never signs from him that he was really hurting. That never got to my ears.”

Hearing Looper describe the sensation inside his shoulder made it sound like pain was an issue. The problem was caused by two bones rubbing together, and Looper said it felt like “having a quarter-inch rock in your shoe and running with it all the time.” The condition got progressively worse during the season, and Looper noticed it most when trying to “finish” his .pitches.

So instead of throwing a sinker that dropped sharply to a hitters’ shins, the pitch stayed up in the zone.

From Jose Reyes’ lost 2004, to Mike Cameron’s slow recovery from a wrist injury during the past off-season, and finishing with the above revelations about Looper’s ordeal, the Mets’ medical staff have quite a recent run.