An untimely arm injury has forced Mark Munoz out of his upcoming bout with Chael Sonnen at UFC on FOX 2 on January 28th in Chicago, Illinois. Sonnen will now face off against Michael “The Count” Bisping on the card. UFC President Dana White announced the change on Twitter today.

The revised fight between Sonnen and Bisping will serve as a number one contender’s bout, with the winner moving on to challenge Anderson “The Spider” Silva for the UFC Middleweight Championship. Bisping’s original opponent, Demian Maia, now awaits a replacement foe for the event.

Sonnen (26-11-1) came within two minutes of capturing the title from Silva when the two first faced off at UFC 117 in August 2010. However, despite his four-plus rounds of dominance, Sonnen fell victim to a fifth-round triangle armbar that dashed his title hopes. A subsequent suspension for elevated levels of testosterone and a brush with the law over charges of money laundering and mortgage fraud kept the outspoken wrestler out of the cage until his return this past October at UFC 136. There, he controlled military veteran Brian Stann through nearly two rounds before submitting him with an arm-triangle choke. Sonnen has won four of his past five fights.

Bisping (22-3-0) has campaigned for a shot at the UFC’s 185-pound title for over two years, but untimely losses to Dan Henderson and Wanderlei Silva resulted in setbacks for the British standout. He has rebounded with four straight victories, however, including a lopsided TKO win over fellow TUF 14 coach Jason “Mayhem” Miller in December. Of Bisping’s 22 wins, 18 have come by stoppage and the bout with Henderson remains the only time that he has ever been finished. He now faces a late change in opponent from jiu-jitsu ace Maia to the wrestling powerhouse Sonnen, but a win would place Bisping in line for his long-awaited title shot.

UFC on FOX 2 takes place on January 28, 2012 at the United Center in Chicago, Illinois.

(Photo Credit: Sherdog.com)