Is Crossbones The Big Bad In "Captain America: Civil War"?

We know that "Captain America: The Winter Soldier" co-star Frank Grillo is set to return in future Marvel films to reprise his role as S.H.I.E.L.D; operative Brock Rumlow, who becomes the villain Crossbones.

Grillo has said that he knows "less then (sic) nothing" about his future arc in the Marvel Cinematic Universe.

Now, Variety reporter Justin Kroll took to Twitter to reveal that Grillo has a more vital role to play in "Captain America: Civil War" than you might think. In fact, he may be the film's primary bad guy:

Beat by Marvel in that one, two things he will play villain but not main one, Crossbones still main
— Justin Kroll (@krolljvar) November 14, 2014

Kroll wrote that in response to a tweet about the recent casting of Daniel Brühl in a villain role that is rumored to actually be the main nemesis seen in the Doctor Strange film.

The 3rd Cap film will be an adaptation of the Captain America: Civil War storyline that sees Iron Man (Robert Downey Jr.) at odds with Captain America (Chris Evans) over the Superhero Registration Act - a law that forces anyone with superhuman abilities to reveal their identities to the U.S. government and agree to act as a police force for the authorities. Stark supports the program, Rogers does not because it threatens civil liberties. As a result Rogers and various others go on the run to avoid arrest. The life of Cap's girlfriend, Agent 13  (Revenge star Emily VanCamp), is torn apart as her superiors use her divided loyalties against her. Elsewhere, a new villain emerges; the Red Skull begins to make himself known; and The Winter Soldier (Sebastian Stan) again comes face-to-face with Cap....

Badass Digest says that despite the presence of RDJ's in the film Stan's Winter Soldier is still a central figure in the action.

 Chadwick Boseman will also be playing Black Panther in the film before getting a solo flick all to himself. Samuel L. Jackson's Nick Fury and Scarlett Johansson's Black Widow are also due to return. Anthony Mackie is poised to reprise the role Harlem crime fighter Falcon

The adapted script comes from Cap vets Christopher Markus and Stephen McFeely from which Captain America: The Winter Soldier directors Anthony and Joe Russo will call action.

Production on the next film is slated to begin next April in Atlanta, Georgia. The studio has targeted a May 6th 2016 release.