Welterweight fighter Thiago “The Pitbull” Alves (16-6) has been forced to withdraw from his bout with Jon Fitch (19-3-0(1)) due to a knee injury. Both men had been scheduled to meet at UFC 107 on December 12.

FanHouse.com reported the news on Friday saying that Alves suffered a torn posterior cruciate ligament while training and will be out 3-4 weeks. Alves’ manager Dan Lambert says the fighter will be ready to step back into the cage anytime after Jan. 1.

The Alves-Fitch fight was announced just a week ago after Fitch’s original opponent, Ricardo Almeida, pulled out of their UFC 106 fight due to a knee injury.

The current UFC 107 card appears as follows:

Main Card

B.J. Penn vs. Diego Sanchez — UFC lightweight title
Cheick Kongo vs. Frank Mir
Jon Fitch vs. TBD
Kenny Florian vs. Clay Guida
Paul Buentello vs. Todd Duffee

Preliminary Card:

Alan Belcher vs. Wilson Gouveia
Shane Nelson vs. Matt Wiman
Ricardo Funch vs. Johny Hendricks
Lucio Linhares vs. Rousimar Palhares
Edgar Garcia vs. DaMarques Johnson
Kevin Burns vs. T.J. Grant