A forthcoming major motion picture releease, "The Fighter," based on the life of Mickey Ward had a change in casting. Ward will still be played by Mark Wahlberg, but the flick will now co-star Brad Pitt as Ward's trainer and half-brother, Dick Ecklund.  That role was originally cast for Matt Damon but the Bourne Identity star had to drop out because of scheduling conflicts. "The Fighter" will concentrate on street life in Lowell, Massachusetts, and Ward's eventual rise to boxing glory.  The film will be a Paramount Pictures release with Darren Aronofsky directing.   As a critically acclaimed director, Aronofsky is best known for directing the films "Requiem For a Dream" and "Pi."