Deadline reports that the actor had a scheduling conflict after production on the movie was delayed, following the departure of director Edgar Wright in May. The actor joined the cast back in February, but it was never confirmed what character he was set to portray.
Two more actors, Matt Gerald and Kevin Weisman, are also parting ways with Ant-Man, but for much different reasons. Their characters were initially a part of Edgar Wright and Joe Cornish's original draft, but they were discarded when the script was rewritten by Adam McKay and the writing team of Gabriel Ferrari and Andrew Barrer.
It remains to be seen if the search to find replacements for these actors will cause yet another production delay, since shooting is scheduled to begin on August 18. Perhaps we'll find out more when Marvel Studios holds hits annual Hall H panel at Comic-Con 2014 tomorrow.