Michael Bay's 'Teenage Mutant Ninja Turtles' Adds Johnny Knoxville as Leonardo, Tony Shalhoub as Splinter

With its release just four months away, you'd think the major parts of Michael Bay's upcoming Teenage Mutant Ninja Turtles reboot would be locked in. Based on the latest casting news, though, fans should expect some significant changes from what they saw and heard in the first trailer that was released last week. According to a Deadline report, Johnny Knoxville and Tony Shalhoub have joined the movie, with Knoxville voicing Leonardo and Shalhoub voicing Splinter.

Up until this point, the actors doing the motion-capture performances for the Turtles and Splinter were also the people voicing the characters. Not only am I guessing that Paramount wanted to punch up the film with a few recognizable voices, I wouldn't be surprised if we soon hear that the studio has brought on big names to voice Donatello, Michelangelo and Rafael.

Teenage Mutant Ninja Turtles already stars Megan Fox, Will Arnett and William Fichtner. Bay is producing with Jonathan Liebesman directing. The movie is set to open on Aug. 8, but there have been rumors that it could get pushed back until the holidays. The news that Paramount is tinkering with the voices of the Turtles themselves kind of backs that theory up.