Anthony Waldburger has been forced to withdraw from his bout from with Matt Riddle at UFC 124 on Dec. 11 at the Bell Centre in Montreal. Riddle’s manager, Malki Kawa, tweeted the news on Tuesday, relaying that Riddle's new opponent had not yet been announced.

A contestant on “The Ultimate Fighter 7,” Riddle is coming off back-to-back victories inside the Octagon. Only 24 years old, Riddle had no professional experience before being cast on the Spike TV reality series. He made his pro debut at the series finale, defeating the more experienced Dante Rivera by unanimous decision. Riddle has only finished one fight; he knocked out “The Ultimate Fighter” Season 9 finalist DaMarques Johnson at UFC Live 2 in his most recent outing. The lone loss on Riddle's record came courtesy of Englishman Nick Osipczak at UFC 105 in 2009. The Brit finished Riddle by TKO late in round three.

Waldburger would have been looking for a fifth straight victory had he not withdrawn from the event due to injury. The native Texan was victorious in his UFC debut, earning a unanimous decision over David Mitchell at UFC Fight Night 22 in September.

UFC 124 will be headlined by a rematch between Georges St. Pierre and Josh Koscheck for St. Pierre's welterweight title. The pair met originally at UFC 74 in 2007, with St. Pierre outwrestling Koscheck en route to a unanimous decision victory.