AceShowbiz -

Iron Man is not a character that can be played by just anyone but Robert Downey Jr., according to Joe Russo. Joe was asked about the possibility of recasting the high-tech armed superhero during an interview with Forbes.

The interviewer asked, "There has been talk of recasting some key roles, Iron Man for example. How much of a big decision is that, creatively and financially, and how much does it change the dynamic?" Joe replied, "It's almost impossible to replace Robert, he's the biggest movie star in the world. One close up from Robert is worth another actor's entire performance, he's incredibly gifted and insanely talented."

Joe revealed that Iron Man might disappear when Robert is done with Marvel. "I think if and when he is done with the character I think you will find that Iron Man might disappear for a while," he explained.

Of a possible "Iron Man" reboot, Joe said, "I think the only way that you could reboot that character is to give a generational gap that would allow another actor to at least have a chance to redefine that character without the enormous spectre of Robert hanging over it. There are so many characters in the Marvel universe that can pick up the ball and run without it through the next phase or two before you need to see Iron Man again, frankly."

In a recent interview with USA Today, Robert revealed that "Iron Man 4" would likely not happen. "I don't think that's in the cards," the actor said, "In a way it's 'Cap 3' but for me it's like my little 'Iron Man 4'. And then it's back to the thing we all recognize. Everything pulls over to the side of the road when the thunder of an Avengers thing comes through because that's how it is until it changes. If it changes."

Robert will reprise his role as Tony Stark a.k.a. Iron Man in upcoming "Captain America: Civil War", set to hit U.S. theaters on May 6.