Mark Munoz, who made an impressive debut in World Extreme Cagefighting this past June, has been forced to drop out of his upcoming fight against Steve Steinbeiss at WEC 36 on Sept. 10 due to an undisclosed injury.

Munoz's departure from the fight was confirmed to MMAWeekly.com by sources close to the fight.

With a relatively thin light heavyweight division, the winner of the Munoz-Steinbeiss fight could have been a favorite to face new WEC champion Steve Cantwell, but for now at least Munoz will have to wait on that opportunity.

Steinbeiss, who trains with the Arizona Combat Sports team, could remain on the card although at this time no new opponent has been announced.

The co-main events for the upcoming WEC show in Florida will be a pair of title bouts as Urijah Faber puts his 145-pound divisional championship up for grabs against Mike Brown and Paulo Filho returns to action to face Chael Sonnen for the middleweight title.

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