“Very focused right now,” UFC welterweight champion Georges St.Pierre wrote yesterday as he sparred with his training partners at the Tristar gym in Montreal, Canada just 12 days out from his fight with Carlos Condit at UFC 137.

However, just hours later he had pulled out of the fight, forcing the main event to be scrapped and BJ Penn Vs Nick Diaz to be moved up to replace it.

What happened in those hours in-between?  GSP’s coach Firas Zahabi reveals the reason – a simple attempt to sprawl to stuff an opponents takedown attempt had sprained his knee, leaving him to limp out of the training session.

Zahabi immediately knew that there was no way St.Pierre was going to recover in time for his fight which was less than a fortnight away.

“I’ve been around, I’ve seen injuries, and I know that that kind of injury is going to take at least two to five weeks of not standing on it for it to be really good (and) sturdy to fight. That’s just me estimating with what I’ve seen in the past,” Zahabi told MMAJunkie.

A trip to the doctor’s for an MRI scan confirmed Zahabi’s suspicions.

“Went straight from Tristar to the doctor this afternoon, very frustrated. Can’t wait to get back at it. Tks for all the support, means a lot,” GSP wrote on Twitter afterwards.

The good news is that it doesn’t appear to be a serious injury that will keep him out for an extended period, and with his opponent Carlos Condit willing to wait it should hopefully only be a matter of months before the two do finally meet in the Octagon to battle for the welterweight title.