Mets reliever Duaner Sanchez has a broken bone in his pitching shoulder and is expected to be sidelined until at least midseason.

Sanchez hasn’t pitched for New York since July, when he separated the same shoulder in a taxi accident and had surgery. Before that injury, he was having a stellar 2006 season as the primary setup man for closer Billy Wagner.

The right-hander, disciplined in spring training this year for repeated tardiness, felt a pop in his right shoulder Thursday and cut short his first bullpen session in eight months after 11 pitches.

He said he didn’t feel any major pain on the pitch, and he was examined by Dr. Dan Tomlinson, who said scar tissue had broken loose. The pitcher was treated with ice.

But Sanchez flew to New York last weekend for an MRI exam and was diagnosed with a hairline fracture of a small bone in the front of his right shoulder.

Surgery is recommended, the Mets said yesterday, and the procedure involves securing the bone with a small screw.

Sanchez probably could resume his rehabilitation within six to eight weeks after surgery. Another six to eight weeks after that, he could begin throwing in a competitive situation.

Sanchez went 5–1 with a 2.60 ERA last season, helping the Mets build a big lead en route to their first NL East title since 1988.

After his taxi accident in Miami and the surgery that followed, Sanchez reported to camp overweight this year. He was sent home for two days by manager Willie Randolph after repeatedly showing up late for rehabilitation.

General manager Omar Minaya also said the club was concerned about changes in Sanchez’s throwing motion after the surgery.

The Mets’ strong bullpen was a big reason they advanced to Game 7 of the NL championship series last year before losing to St. Louis. The unit was expected to be a strength again this season, but it will certainly have a different look.

Chad Bradford signed with Baltimore, Darren Oliver joined the Los Angeles Angels, and Roberto Hernandez left for Cleveland. Heath Bell and Royce Ring were traded to San Diego for reserve outfielder Ben Johnson and another reliever, Jon Adkins.

In addition, Guillermo Mota will miss the first 50 games while serving a steroids suspension. And hard-throwing right-hander Ambiorix Burgos, acquired from Kansas City in an off-season trade for Brian Bannister, has been a disappointment in spring training.