Well, being Pete Ploszek must suck right now. The little-known Shameless star looked set to find his big break with a starring role as Leonardo in Teenage Mutant Ninja Turtles, and despite the fact that he was the one who donned the motion capture costume on set, he has now been replaced by Jackass star Johnny Knoxville as the voice of that character. However, Deadline reports that he's not the only one getting replaces as Seinfeld's Danny Woodburn - who also played Splinter during shooting - has been switched out in preference of Monk star Tony Shalhoub. Apparently, the studio were always open to changing the voice-over artists of these characters, but whether or not the actors playing them knew that is another thing altogether. Directed by Jonathan Liebesman, Teenage Mutant Ninja Turtles is set to be released on August 8th, 2014.