One WWE source noted to PWInsider that the company ignored Batista being in Guardians of the Galaxy because he wasn’t on their TV as a performer.
Apparently the Guardians producers didn’t want to buy WWE advertising for the movie. One source in WWE speculated that Marvel didn’t want the movie to become a “wrestler movie.”
There’s also a feeling within WWE that the company downplayed Batista in Guardians because they feel he’s not coming back any time soon.
