Following conflicting reports throughout the morning, American Top Team has officially confirmed that top welterweight contender Thiago “Pitbull” Alves has suffered a torn knee ligament in training. He will be unable to compete in a rematch with Jon Fitch at UFC 107 and a replacement opponent for Fitch is being sought.

Alves was defeated by Fitch in the pair’s first meeting at UFC Fight Night 5 in June of 2006 and aimed to avenge the loss, but will have to wait until next year to get a second shot at Fitch.

Fitch (20-3-0, 1 NC) was first scheduled to face Ricardo “Big Dog” Almeida at UFC 106, but Almeida pulled out of the fight after suffering a knee injury himself. A rematch between Fitch and Alves, two of the top contenders in the UFC’s competitive welterweight division, was quickly set in motion.

Alves (16-6-0) has lost just once, in a five-round title fight against UFC Welterweight Champion Georges “Rush” St. Pierre, since his first meeting with Fitch. He stopped Karo Parisyan and Matt Hughes, then dominated Josh Koscheck en route to the showdown with St. Pierre.

Fitch and Alves share the distinction of losing one-sided decisions to St. Pierre, but both fighters showed huge heart in never giving up in their battles with the Canadian star.

A replacement opponent for Fitch has yet to be named, but an announcement is expected in the coming weeks.

UFC 107: “Penn vs Sanchez” is headlined by a UFC Lightweight Championship bout between “The Prodigy” BJ Penn and Diego “Nightmare” Sanchez. It takes place on December 12th at the FedEx Forum in Memphis, Tennessee.