One of the members of the team that Captain America worked on with S.H.I.E.L.D. and Black Widow was Brock Rumlow, played by Frank Grillo, who would be heading to the hospital on a stretcher at the end of the movie. But is that a tease to a future Marvel villain?

Could There Be A Connection Between 'Agents Of S.H.I.E.L.D.' & 'Captain America 3?'

In the comics, Rumlow turns into Crossbones, an assassin who works for the Red Skull. Crossbones assembled the Skeleton Crew from the Skull's henchmen and became their leader, searching for the missing Red Skull with them.

They battled the Black Queen and her Hellfire Club mercenaries. Crossbones enlisted the aid of psychic Tristam Micawber to locate the Skull. Upon finding him, Crossbones took the Skull to Skullhouse for convalescence.

Another Avenger Could Pop Up In 'Captain America 3' To Help The Team

While Grillo hasn't spoken much about his future with the franchise, having his character transform into Crossbones and go and look for the Red Skull could be a possible side-plot for the next movie. It would also allow the return of one of Captain America's most famous villains to return and help bring the end of the series.

Grillo has showed that he can match the action of the other stars like Chris Evans, Anthony Mackie and Sebastian Stan. He had a fist fight with Mackie at the end of Winter Soldier that ended with him hurt, but showed that he can bring the superhero fight as well as the others.

Captain America 3 is bringing back Anthony and Joe Russo to direct and is set to open in theaters on May 6, 2016.

Tags: Captain America Movies Frank Grillo