Mac Danzig tore a muscle while training, forcing him to withdraw from his upcoming lightweight fight with Donald Cerrone at UFC 131 in Vancouver, British Columbia, Canada, on June 11, according to MMAWeekly.com.

No replacement is known at this time; however, "Cowboy" is still expected to compete on the card against a soon-to-be announced opponent.

This is the latest setback for Danzig, who won The Ultimate Fighter (TUF) season six back in Dec., 2007 and showed all the promise in the world with his dominant win over Tommy Spear. In his next fight, he submitted Brazilian jiu-jitsu specialist Mark Bocek, seemingly solidifying his status as a threat to anyone in the crowded 155-pound division.

However, it was all downhill after that -- Danzig promptly lost four of his next five bouts.

He then went strolling into his UFC 124 clash against Joe Stevenson with his job on the line. With his back pressed firmly against the wall, the Ohioan came out swinging and put "Daddy" down for a nap with a one-hitter quitter that won him "Knockout of the Night."

Now he's on the mend, hoping to keep the momentum alive whenever he's healthy enough to return to the Octagon.

UFC 131 features a re-worked main event of massive proportions when Shane Carwin steps in for the injured Brock Lesnar to battle Brazilian bomber Junior dos Santos for the right to face Cain Velasquez for the heavyweight championship later this year.

Mark Munoz is also booked to face Demian Maia, while Kenny Florian will make his featherweight debut against wily scrapper Diego Nunes.

To check out the latest UFC 131 news and notes check out our event archive right here.