This May's "Captain America: Civil War" marks Scarlett Johansson's fifth appearance as Black Widow. As all of those appearances have been in supporting roles, you can add one more name to the long list of people calling for a Black Widow standalone film: "Agents of S.H.I.E.L.D." lead actor Clark Gregg. While talking to Digital Spy, Gregg went to bat for his "Iron Man 2" and "Marvel's the Avengers" co-star, saying that Marvel would be wasting a valuable asset by not giving Black Widow the spotlight.

"Black Widow has been around from day one of this..." said Gregg, "...and is portrayed with this kind of heavy-hearted ferocity by Scarlett Johansson -- who I think is as good as any actor working today. It seems like it would be tragic, it would be a waste, if that character wasn't given the spotlight in the way that some of the other characters have been. If I know Marvel, they won't let that happen, because she's too valuable an asset."​

Johansson talked about the possibility of a Black Widow movie last April, before the release of "Avengers: Age of Ultron."

"I've spoken to [Marvel Studios president] Kevin [Feige] about it," she said last year. "I mean, of course, of course we've had that conversation before, and I think Kevin would also like to see a standalone film. I think I can speak for him and say that. That's all, really. Right now I think this character is used well in this part of the universe, but I think that Kevin -- I mean, we've talked about it and we both share similar vision for what could be a standalone series."

Iron Man himself, Robert Downey Jr., has also talked about wanting to see Black Widow take charge. "Doesn't Scarlett deserve a break?" Downey Jr. said in a 2014 interview. "It would be kind of more appropriate for a character that already was like a Black Widow [to lead a movie]. It just seems like whatever Scarlett does people want to go see it."

Black Widow next appears in "Captain America: Civil War," opening on May 6, 2016.