Former UFC heavyweight champion Frank Mir (Pictures) has fallen off April 5's UFC Fight Night Card with an undisclosed injury, Sherdog.com learned Wednesday. Taking the 27-year-old Mir's place versus Dutch striker Antoni Hardonk is UFC newcomer Justin McCully.

Mir (9-3-0) has fallen hard since suffering serious leg injuries stemming from a motorcycle accident in Sept. 2004. Returning to the Octagon last year, Mir went 1-2, losing in the first round to Marcio Cruz (Pictures) and Brandon Vera (Pictures) while taking a close decision against Dan Christison (Pictures).

McCully (7-3-2) had not fought for three years before winning twice in Oct. 2006. Losing to Evan Tanner (Pictures) in the finals of Pancrase's 1998 New-Blood tournament, McCully fought actively until 2000. Today he is best known for being a training partner of former UFC light heavyweight champion Tito Ortiz (Pictures).