According to one Gracie official, Monson separated his shoulder in training and is scheduled for surgery this Thursday.
Monson was originally scheduled to face UFC veteran Wes Sims, but contractual issues kept Sims off the card. The fight was rescheduled against Brian Vanderwalle, but is now off the card due to Monson's injury.
Gracie Fighting Championships Fight Card:
GFC Welterweight Championship Bout
Fredson Paixao vs. Thomas Denny
Jacare vs. Bill Vucick
Branden Lee Hinkle vs. Alexandre Ferreira
Adam Disabato vs. Chris Brennan
Damian Maia vs. Ryan Stout
Phil Cardella vs. Rafael Dias
Adriano Pereira vs. Mike O'Donnell
George Bush vs. Vinicius Magalhaes
Matt Brown vs. Daniel Moraes
Nissen Osterneck vs. Chris Meyers
Leopoldo Serao vs. Rob Wince