Last night on "Late Night with Jimmy Fallon," "Avengers" director Joss Whedon joined the talk show host and briefly discussed the inclusion of Quicksilver and Scarlet Witch in the film's sequel.

Whedon called them "great mainstays in the Avengers when I was reading the comics as a kid." Whedon said they have not yet been cast -- and didn't mention anything about Quicksilver being cast in the upcoming "X-Men: Days of Future Past" film from Fox -- but Fallon suggested that Whedon cast Selena Gomez and Channing Tatum as the brother and sister duo.

"Their powers are very visually interesting," Whedon said about the pair, noting that in the first movie "everybody had 'punchy' powers," and that with them on the team, "there's good stuff that they can do that'll help to sort of keep it fresh."

Whedon also talked about his work on "Much Ado About Nothing," which has its North American theatrical release on June 7. Watch the clip below.