According to his wikipedia page, Jarvis Moss was considering retirement and came back because of Rick Ross.
http://en.wikipedia.org/wiki/Jarvis_Moss
http://en.wikipedia.org/wiki/Jarvis_Moss
It was rumored that he was chided into returning by gangster-rap artist Rick Ross in an internet exclusive diss-track entitled "I'm the only one whoz name should rhyme with hoss." In the track Ross raps how Jarvis is a disgrace and looked like a botsy-boy (rastafarian) for being sweet, while chasing Troy Smith around in the Florida Gators victory over Ohio State Buckeyes in the 2007 BCS game.
During high school he acquired a staph infection which was not found and treated until midway through his collegiate career.
Why is everyone so unhappy in Denver? I wonder what the hell Josh McDaniels is doing over there....