Robert Downey Jr says Captain America 3 is going to be 'huge.'
Downey Jr could well be reprising the role of Tony Stark in the film, while that news is yet to be confirmed, he is believed to be in talks.
This would mark the first time that Iron Man has appeared in a Captain America movie as he would reunite with Chris Evans.
When asked by Yahoo UK if he was going to appear in the film, Downey Jr said: "Yeah, that sounds very exciting.
He was pushed a little further and went on to say: "If I do, I’ll just regret it... It’s gonna be huge, whatever it is."
Captain America 3 is set to hit the big screen in 2016, and will see Anthony and Joe Russo return to the director's chair.
It is thought that the movie may explore the Superhero Registration Act with Captain America and Iron Man on different sides of the argument.
And Downey Jr may not be the only familiar face in the film, as Jeremy Renner has also been tipped to make an appearance as Hawkeye.
Evans and Downey Jr will reunite for the first time since Avengers Assemble next year with Avengers: Age of Ultron set to hit the big screen.
This will be Downey Jr's first outing as Stark since the billion dollar success of Iron Man 3 in 2013.
As for Evans, he reprised the role of Captain America earlier this year in Captain America: The Winter Solider, which was both a critical and commercial success.
The Winter Solider is the fourth highest grossing Marvel film of all time, behind Avengers Assemble, Iron Man 3, and Guardians of the Galaxy.
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