The list of potential opponents for Anderson Silva seems to be shrinking by the day.

As recently as six months ago the middleweight division seemed to be stronger than it has ever been, and it appeared Silva had a brand new batch of contenders to deal with at 185.

Now, it appears to be Michael Bisping or bust.

Just when it looked like the middleweight division was finally coming into its own, the last few months have seen the 185-pound ranks decimated by injuries and those same new contenders suffer momentum-killing losses.

There were several key bouts that helped the division fall back into its slump. But if the division is completely barren in a few months, UFC 155 may be the event we look back on as the one that killed the weight class.

It started with top prospect and potential title challenger Chris Weidman.

The Team Serra-Longo member made a huge statement to the rest of the contenders with his absolute decimation of Mark Munoz at UFC on Fuel 4 in July, and he quickly found himself on the short list to get a crack at Silva.

But when Silva seemed determined to try and get himself a super fight with welterweight champ Georges St-Pierre, Weidman agreed to take a fight with fellow contender Tim Boetsch on the UFC’s year-end card. But an injury suffered in training forced Weidman from the card, and Boetsch ended up fighting a much smaller name in Costa Philippou.

After back-to-back wins over Yushin Okami and Hector Lombard, Boetsch was expected to keep building momentum and add another name to his growing resume. Unfortunately for Boetsch, Philippou had other plans and the New York native defeated “The Barbarian” and erased another name from the list of potential title challengers.

Sadly, Boetsch wasn’t the only top contender to find himself tumbling back down the middleweight ladder last Saturday night.

Alan Belcher, who finally seemed to be reaching some of that untapped potential that fans had seen for years, was looking to avenge a loss to Yushin Okami that he suffered back in his UFC debut over six years ago. However, the rematch between the two longtime UFC middleweights ended up looking almost identical to the first match-up, as Okami used his superior grappling to completely shut down Belcher’s explosive offense.

With Belcher also getting knocked out of the title picture, the list of potential title challengers at 185 has basically come down to one guy.

If Michael Bisping beats Vitor Belfort later this month, he’ll get the next shot at Silva.

“The Count” has paid his dues in the middleweight division for years, never quite earning the wins needed to get in the cage with Anderson Silva, but always having his name come up when potential title challengers are discussed.

Key losses to Dan Henderson and Chael Sonnen have slowed Bisping’s rise to the top of the division, but his performances against higher-quality opponents keeps on improving and it looks like he may be ready to get himself over the hump by taking out Belfort.

Beating “The Phenom” in his home country of Brazil isn’t going to be an easy task, but if Bisping is ever going to get a shot at winning a UFC belt, he has to cash in now.

Since Weidman, who’s stuck on the sidelines, is the only other middleweight on the roster that could possibly make a case for a title fight right now, the door is wide open for Bisping to step in and earn a shot at taking out the best in the world.

This is the opportunity that Bisping has been looking for his entire UFC career, and the Zuffa brass better hope he makes the most of it, or Silva could end up sitting out most of 2013 waiting for someone to prove himself worthy to fight “The Spider.”

Photo: Michael Bisping (James Law/Heavy MMA)