Rousimar Palhares has been forced out of next month’s UFC 150 event in Calgary with a knee injury sustained during his training camp.

Palhares had been set to face Yushin Okami, but he’s now likely to be out for some time and may require surgery.

His loss is Buddy Roberts gain as he’s now been called upon to step in to face Okami instead in what’s undoubtedly his biggest fight to date.

The 29 year-old Roberts made a successful start to his UFC career in June when he picked up a unanimous decision victory over Caio Magalhaes. That extended his current unbeaten run to six fights, and improved his pro-record to 12-2 overall.

Okami on the other hand finds himself in the unusual position of coming off back-to-back losses for the first time in his 33 fight career.

He first suffered a convincing loss to Anderson Silva in August of last year at UFC 134. Then at UFC 144 in his native Japan he appeared to be en-route to an impressive win over Tim Boetsch before ‘The Barbarian’ produced one of the comebacks of the year and TKO’d him early in the third round.

Prior to that Okami had been defeating the likes of Nate Marquardt and Mark Munoz, and he’ll be keen not to slip up against Roberts and get back to higher profile fights like those as soon as possible.