Canadian fighter Georges St-Pierre will be out of action for almost a year after suffering a serious knee injury.
UFC president Dana White issued a tweet Wednesday that said St-Pierre will not fight Nick Diaz at UFC 143 on Super Bowl weekend.
"GSP blown acl will be out for 10 mos. Now Condit vs Diaz for the interim welterweight title on Feb 4th in Las Vegas!!" White wrote.
The news came about six weeks after St-Pierre suffered a strained knee ligament while training in his hometown of Montreal.
The injury forced him out of a UFC 137 title fight with Nick Diaz.
St-Pierre (22-2) has battled knee injuries before.
After beating Matt Hughes for the championship at UFC 65 in November 2006, he lost the title to Matt Serra at UFC 69 in April 2007 in a fight that was delayed two months due to a GSP knee issue.
St-Pierre won it back from Serra at UFC 83 in April 2008. The Canadian has defended the welterweight championship six times since.
St-Pierre also tore his abductor muscle in three places in a victory over Thiago Alves at UFC 100 in July 2009.
The UFC has been hit hard by injuries over the last year, reflecting a hard-nosed sport where the training can be tougher than the fights themselves.
Lightweight champion Frank Edgar's recent title defence against Gray Maynard was delayed when both fighters were injured in the leadup. Former heavyweight champ Cain Velasquez missed several months after shoulder surgery.
Light-heavyweight champion Jon (Bones) Jones, former light-heavyweight title-holder Rashad Evans and former heavyweight champ Brock Lesnar (diverticulitis) have also been sidelined for varying amounts of time.
Jones is scheduled to fight Lyota (The Dragon) Machida in the main event of UFC 140 this Saturday at Air Canada Centre in Toronto.
