Here's what Josh Duhamel had to say in a recent interview.
"[Michael] said he wants to put me in it someplace. I don't know if he was just saying that because he had me on the phone and he felt obligated or what, but you know what? I got to do three of those. It changed my career, it changed my life getting to be a part of something that big, so I'm grateful for even doing the first three of them."
Last month, producer Lorenzo di Bonaventura revealed that a Shia LaBeouf cameo may be possible, if something within the story evolves naturally. As of now, the only confirmed cast members are Mark Wahlberg, Nicola Peltz, and Jack Reynor. It isn't known when production will begin on Transformers 4.
Transformers: Age of Extinction was released June 27th, 2014 and stars Nicola Peltz, Mark Wahlberg, John Goodman, T.J. Miller, Stanley Tucci, Kelsey Grammer, Sophia Myles, Jack Reynor. The film is directed by Michael Bay.