We’ve been hearing about Jake Gylenhaal’s serious muscle gain for his Southpaw flick, and today the trailer arrives for the boxing drama. Directed by Anthony Fuqua, the film also stars Forest Whitaker, 50 Cent, Rachel McAdams, Tyrese, and Rita Ora. The trailer teases new music from Eminem, (who was originally cast in the lead role). Southpaw will arrive July 31.