This comes from Fighters.com...
Former UFC heavyweight champion “Maine-iac” Tim Sylvia (24-6) is currently in Boston playing horror film icon Jason Vorhees in the yet-to-be-titled “Friday the 13th” sequel, Fighters.com has confirmed with a source close to the fighter.
But, before you get angry about the possibility of Derek Mears be replaced, keep reading, because the article goes on to say...
Sylvia is one of the actors standing-in as the hockey mask-mugged serial killer in the movie franchise began in 1980 and spanning 12 volumes.
Note the made "standing-in" in bold. Because that's exactly that. He's a STAND-IN. Which he means he most likely will have ZERO screen time and is only standing in Mears' place while they set up a new scene/shot.
Also, this rumor may be completely BS anyway since the Friday the 13th sequel has yet to begin production. Let me know your thoughts by commenting.