He became known to audiences for playing Bucky Barnes in Captain America: The First Avenger. His role in the miniseries Political Animals earned him a Critics' Choice Television Award for Best Performance by a Supporting Actor. In 2015 he portrayed Chris Beck in the film The Martian.
He spent a year abroad studying theater at Shakespeare's Globe Theatre in London.
He did all his own stunts in the movie The Covenant.
He was in Darren Aronofsky's film Black Swan.