Former welterweight title challengers Jon Fitch and Thiago Alves will have to wait for their rematch, as an injury has forced the Brazilian to withdraw from a scheduled bout at UFC 107 “Penn vs. Sanchez” on Dec. 12 at the FedEx Forum in Memphis, Tenn.

American Top Team owner Dan Lambert on Friday confirmed Alves' withdrawal to Sherdog.com via text message. Lambert said Alves suffered a “small” tear to the posterior cruciate ligament in his knee.

“He wanted to fight regardless,” Lambert texted, after some confusion on Friday, when it was speculated Alves might remain in the bout after all. “You can’t miss 3-4 weeks training against a guy like Fitch to heal an injury. He’s out, but good to go after the first of the year.”

FiveOuncesofPain.com, which was first to break the news, also reported that a replacement for Alves will be sought.

This marks the second change in opponent for Fitch in little more than a week. He was originally slated to meet former middleweight King of Pancrase Ricardo Almeida, who pulled out of their UFC 106 clash with a knee injury.

Based at the American Kickboxing Academy, Fitch last competed at UFC 100 in July, when he earned a unanimous decision against the previously unbeaten and world-ranked Paulo Thiago. The 31-year-old Fort Wayne, Ind., native has posted 17 wins in 18 fights, losing only to reigning UFC welterweight champion Georges St. Pierre in that span.

Still only 26, Alves has not appeared in the Octagon since his unanimous decision loss to St. Pierre at UFC 100 three months ago. The defeat snapped a seven-fight winning streak for the American Top Team-trained “Pitbull.” Victories against former UFC welterweight king Matt Hughes, the world-ranked Josh Koscheck and Karo Parisyan anchor his resume.

A lightweight title bout pairing champion B.J. Penn with “The Ultimate Fighter 1” winner Diego Sanchez will headline UFC 107.

This story was updated at 1:24 p.m. ET on Friday, with confirmation and additional information from American Top Team.