'Captain America 2' (aka 'Captain America: The Winter Soldier') has been working hard to find the right actress to star as Agent 13/Sharon Carter in the upcoming superhero sequel. A number of names have been rumored for the part including Alison Brie, Imogen Poots and Teresa Palmer. But none of these actresses have tested for the part yet? And why not? Because another actress not on any of the previous lists may have already snagged the role.

Latino Review is reporting that Mary Elizabeth Winstead is currently Marvel's top choice to star as Agent 13 in 'Captain America 2' and she's the reason why Brie, Poots, Palmer and the like have yet to actually read for the role.

Winstead can be seen this weekend in 'Smashed,' a movie many think could bring the 'Scott Pilgrim' actress her first Oscar nomination. While she's starred in action films before (see: 'Live Free or Die Hard'), 'Captain America 2' would be her first role being a major part of the action (though we did leave quite impressed with this fight scene in 'Scott Pilgrim').

Sharon Carter is the niece of Peggy Carter, the love interest of Cap in the first film (played by Hayley Atwell). She works with Nick Fury as an agent of S.H.I.E.L.D. (Agent 13) and is the current love interest for modern day Captain America.

The same report also mentions that Josh Holloway ('Lost') and Nikolaj Coster Waldau ('Game of Thrones') are also up for parts in the new film, roles still yet unknown.

'Captain America 2' is set for an April 4, 2014 released date.