A bit of a casting switcheroo is taking place on Robert Luketic’s (21) diamond heist-thriller Brilliant. Variety reports that Gerard Butler is replacing Eric Bana as the star of the film, as Bana apparently bowed out after previously entering negotiations last fall. The story involves a small-time criminal who joins up with polished thieves in order to attempt a diamond heist. The logline isn’t exactly thrilling and Luketic’s filmography includes Legally Blonde and The Ugly Truth, so Bana may have been on to something when he vacated the project. The film may have a more intriguing hook that they’re keeping close to the vest, but its success will probably hinge on who they cast to team up with Butler. Producers are currently looking for a female lead and I sincerely hope Luketic doesn’t feel compelled to pair Butler with Katherine Heigl once again.The 300 actor has quite a few films on the horizon. He’s already completed the surfing pic Of Men and Mavericks and the romantic sports comedy Playing the Field, and he’s poised to star in Antoine Fuqua’s Hunter Killer, the 3D motion-capture war movie Thunder Run, and a fact-based mercenary pic for director Ridley Scott.