Josh Neer will replace an injured Sean Sherk in a lightweight bout against Gleison Tibau at UFC 104 on Oct. 24 in Los Angeles, according to a source close to the matchup.

Sherk, 36, suffered a shoulder injury in training that will keep him out of the gym for approximately four weeks, according to his manager Monte Cox. The injury is a setback for the former lightweight champion, who is 1-1 in his last two Octagon appearances since failing to recapture the crown from B.J. Penn at UFC 84 in May 2008.

Neer dropped a tough decision to Kurt Pellegrino at UFC 101 in August and is 2-2 in his last four UFC performances. The tough-as-nails Iowan submitted Mac Danzig in a memorable tilt at UFC Fight Night 17 last February.

Tibau returns to action after a close split-decision loss to Melvin Guillard at “The Ultimate Fighter 9” Finale in June. A wrestler fighting out of Florida’s American Top Team, Tibau had defeated Jeremy Stephens and Rich Clementi before dropping the bout to Guillard.