A heavyweight bout between former UFC champion Tim Sylvia and Jason Riley is in discussions to be the main event of Adrenaline MMA IV on September 18 from the Mid-America Center in Council Bluffs, Iowa.

News of the bout was first broken by Riley himself on his personal MySpace account. The promotion has yet to confirm the bout or even officially announce the event.

Sylvia will be looking to bounce back from a embarrassing nine-second knockout loss to 48-year-old boxer Ray Mercer in a unsanctioned bout at Adrenaline MMA 3 in June; Sylvia came in at a robust 310 lbs for the bout and the loss forced him off the Affliction: "Trilogy" event on August 1 against would be opponent Paul Buentello. The event was later scratched and the promotion has since folded anyway.

Sylvia has now lost three straight, with the other losses coming against Antonio Rodrigo Nogueira in his last bout with the UFC and Fedor Emelianenko at Affliction's first event last year. Sylvia was once a dominant force in the heavyweight division putting together a 23-2 record  from 2001 to 2006, with notable wins over Mike Whitehead, Ricco Rodriguez, Andrei Arlovski and Jeff Monson. Sixteen of his 24 career wins have come by TKO or KO.

Riley is currently on a two-fight win streak, with his most recent coming over Justin Black earlier this year at NAAFS: "Caged Vengeance 4." Since turning pro in 2007 following an undefeated 8-0 stint as a amateur, he has posted a 6-1 MMA record, with his only loss coming against James Sendo last March. Out of his six career wins, 5 have come by stoppage and he holds a notable win over Braden Bice.

Also, according to a report pertaining to the event, UFC veteran Jeremy Horn will compete at the event following a successful outing a Adrenaline MMA 3, where he defeated Chris Davis to break a three fight losing streak. Also slated to for the event is popular UFC fighter Houston Alexander, who received permission to take a bout outside the promotion. Alexander will be looking to snap a three fight losing streak.