Chris Weidman celebrates after beating Mark Munoz in their middleweight...

Chris Weidman celebrates after beating Mark Munoz in their middleweight bout at UFC on Fuel 4 in San Jose, Calif. Weidman won by technical knockout in the second round. (July 11, 2012) Credit: AP

Long Island's Chris Weidman, one of the top UFC middleweight fighters, is out of UFC 155 next month with a shoulder injury, Newsday has learned.

He was scheduled to fight Tim Boetsch on Dec. 29 in Las Vegas. Taking Weidman's place on the year-end card at the MGM Grand Garden Arena will be teammate Costa Philippou. Both Boetsch and Philippou have verbally agreed to the bout.

Weidman said the injury occured Tuesday while training in Arizona with UFC light heavyweight Ryan Bader and Levittown-based Strikeforce light heavyweight Gian Villante. The injury occured during a grappling session, the 28-year-old Weidman said.

"I hit a double-leg and that's it," Weidman said Wednesday. "My shoulder landed weird and I felt a pop. I can't even move my arm."

An MRI performed in Arizona showed Weidman has a torn labrum in his right shoulder. It is a grade 4 SLAP tear (Superior Labrum Anterior Posterior) that will require surgery. Weidman is expected to be out 3-6 months. Weidman said the MRI also revealed a possible separated shoulder, which is caused by damage to the acromioclavicular (AC) ligament.

The labrum is a cuff of cartilage that makes the shoulder joint stable and allows for a wide range of movements with the arm. A SLAP tear extends from the front (anterior) to the back (posterior) of the shoulder. The AC joint is what allows for the ability to lift the arm over the shoulder.

"It's awful," trainer Ray Longo said.

Weidman had recently resumed training for the fight after spending the end of October and beginning of November cleaning up the damage done by superstorm Sandy to his home on the water in Baldwin Harbor. Weidman had bone chips removed from his left elbow in September.

A fellow Serra-Longo mixed martial artist, Philippou was supposed to fight this past Saturday against Nick Ring at UFC 154 in Montreal but the bout was canceled that morning when Ring fell ill.

"Everything happens for a reason," Longo said. "I guess this is the reason."

Weidman (9-0, 5-0 UFC) had emerged as a top contender for Anderson Silva's title with wins over Demian Maia and Mark Munoz.

Philippou (11-2, 4-1) has quietly won four straight in the UFC with his precision striking and improving takedown defense. After losing half of his first six bouts in the UFC, Boetsch (16-4, 7-3) has put together a four-fight win streak including decisions over Hector Lombard, Ring and Kendall Grove, and a third-round TKO of Yushin Okami.

The Boetsch-Philippou bout will remain on the pay-per-view card for UFC 155, headlined by Junior Dos Santos' heavyweight title defense against Cain Velasquez. Other scheduled bouts include Forrest Griffin vs. Phil Davis, Okami vs. Alan Belcher and Chris Leben vs. Karlos Vemola.

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