Tony Shalhoub, Johnny Knoxville join Michael Bay's 'Teenage Mutant Ninja Turtles' movie

The voices of Leonardo and Splinter in Michael Bay's upcoming Teenage Mutant Ninja Turtles movie will have some familiar voices, as Johnny Knoxville and Tony Shalhoub will now voice the two characters, respectively.

Deadline reported the news and points out Pete Ploszek portrayed Leonardo during filming, while Seinfeld's Danny Woodburn (aka Mickey) played Splinter. The site reports the movie was "always open to changing the voicing component" of the film and "those actors were only guaranteed to physically perform the roles in costume."

The movie now stars Megan Fox as April O'Neil, Alan Ritchson as Raphael, Noel Fisher as Michaelangelo, Jeremy Howard as Donatello, William Fichtner as Shredder, Will Arnett as Vernon Fenwick and Abby Elliott as Irma Langinstein.

Jonathan Liebesman directed the film, which hits theaters on Aug. 8.

Here's the official synopsis for the new TMNT:

The city needs heroes. Darkness has settled over New York City as Shredder and his evil Foot Clan have an iron grip on everything from the police to the politicians. The future is grim until four unlikely outcast brothers rise from the sewers and discover their destiny as Teenage Mutant Ninja Turtles. The Turtles must work with fearless reporter April and her wise-cracking cameraman Vern Fenwick to save the city and unravel Shredder's diabolical plan.

What do you think of these additions, Teenage Mutant Ninja Turtles fans? Are Shalhoub and Knoxville the right choices for these characters, or is this movie destined for failure? Let us know your thoughts in the comments below.