Unfortunately, Anthony Pettis has suffered a knee injury that has lead to his lightweight title fight with Josh Thomson being delayed until an as yet unspecified date.

Just 24hrs ago UFC President Dana White had confirmed that Pettis had injured his knee, but had assured the assembled media that he would be healed in time to fight on FOX, but it seems that he spoke prematurely and it’s since transpired that he won’t be ready in time.

White had also indicated following Saturday night’s ‘UFC Fight Night 32′ event in Brazil that Pettis’ knee just required rehab rather than surgery, so hopefully that’s still the case and the title fight can still happen early next year. The 26 year-old has had a lot of trouble with his knees in recent times though, so that’s definitely a cause for concern.

As a result of this, ‘UFC On FOX 9’ in December is now left without a headliner and so the UFC have opted to push back a flyweight title rematch between current champion Demetrious Johnson and Joseph Benavidez to be the main event of the final FOX event this year.

Johnson won the original encounter between these two by a narrow split decision verdict last year and has made two successful title defences since then, while Benavidez has racked up three wins in a row to earn another chance to take the belt.

Johnson Vs Benavidez was originally scheduled to take main event honors at the TUF 18 Finale on November 30th, but will now have to wait an extra couple of weeks before they have a chance to lock horns again.

As it happens, Johnson will now have headlined three of the four ‘UFC On FOX’ shows held this year, though on two of those occasions he’s done so only after stepping in at late notice to cover for a cancelled main event.

Getting to fight in front of millions of viewers on FOX is terrific exposure for ‘Mighty Mouse’, though while the UFC will no doubt be happy to give him that exposure, ideally they’d rather have had significantly more variety in terms of headliners for their most watched shows this year.