WEC Champ Paulo Filho Withdraws from Title Fight

WEC middleweight champ Paulo Filho (16-0) has pulled out of a March 26 title fight and rematch with Chael Sonnen (19-9-1) to check himself into an undisclosed rehabilation center, the organization announced on Thursday.

Filho is seeking help for a substance-abuse problem.The WEC event will now feature a main event between WEC light heavyweight champ Doug Marshall and Brian Stann. It takes place at the Hard Rock Hotel & Casino in Las Vegas, Nev., and airs live in high-definition on the VERSUS network at 9 p.m. ET.

Filho and Sonnen first met in December at WEC 31. Filho kept his undefeated streak alive with a second-round submission via armbar. However, the fight ended with a bit of controversy as Sonnen, who had dominated much of the fight, claimed he never verbally tapped. Sonnen groaned in pain from the submission -- and it was clearly audible to the television audience -- but he said it was never intended to be a verbal tap-out.

Filho, widely regarded as one of the world's top middleweight fighters, first joined the WEC last year after a successful career with PRIDE Bushido. He won the the WEC middleweight title with an August TKO victory over veteran Joe Doerksen.