Terrible thread, but I think it's obvious. Have you ever heard of The Rock?I know Steve Austin was in the 1st Expendables, but I don't why we haven't seen more wrestlers in those movies.
I saw this list of actors who should be in Expendables 4 if they make a sequel: http://whatculture.com/film/expendables-3-10-action-behemoths-franchise-still-missing.php It includes both Roddy Piper and Mr. T. I think that's a good start wrestling-wise.
What about Hogan? Or Goldberg? Or Kurt Angle? All of them were in a few action movies. I think a lot of wrestlers could be in an Expendables-like movie.
Let's start a list!