Board Thread:Questions and Answers/@comment-7657843-20161105172234/@comment-27020644-20161105230715

It would make sense that Warlock would appear. In Guardians of the Galaxy, we saw his cacoon, and in Guardians of the Galaxy Volume 2 we are getting Ayesha AKA Her. So there will definitly be a connection to him.

Warlock could be trapped in the Soul Stone.