Robert Downey Jr. was 'a hundred percent' concerned being in the MCU would affect his acting skills

Robert Downey Jr. says he was worried the Marvel movies would affect his acting skills.

The Hollywood star is one of the biggest names on the planet, no small part thanks to the meteoric success of the MCU.

In 2008, he was cast as Tony Stark in Iron Man, kicking off the comic book franchise.

As you most likely are aware by now, it proved to be a massive success, with Downey Jr. going on to make countless other movies in the series.

However, while the franchise dwarfed cinema and continues to dominate the box office, Downey Jr. admitted recently that he did have some concerns around what it meant for his craft.

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Speaking to the New York Times, the 58-year-old admitted that it came up while filming his upcoming World War Two biopic Oppenheimer.

He said: "Yes. A hundred percent, and I knew there was a point where Chris Nolan was endorsing, let’s work those other muscles, but let’s do it while rendering you devoid of your usual go-to things."

Looking back at that period, Downey Jr. said that there was a certain moment of clarity he experienced where he realised that all the money and success the film brought was still not enough.

Asked when the 'money-prestige illusion dissolved', the Sherlock Holmes star said: "About two weeks after me and Jon and Kevin were pumping fists at Giorgio Baldi, in the private room, and the numbers kept getting bigger for the first weekend of the first Iron Man.

"It was gung-ho, masters of the universe until I went to bed on night 13. I must have processed out all of the projection that had been on those external markers of what I should feel great about. I went into a k-hole."

He went on: "That drive that had been built up by being the kid on the other side of the fence — there was no longer a purpose for that.

"The water broke on what had seemingly been this unrequited thing.

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"These external goals — there’s only so much space on the hard drive to function, and it was all geared toward getting this thing, and then when you meet it, it just goes, OK, big shot, can we get back to the process of unpacking a lifetime of experiences, fears, hopes, desires?"

This comes after fellow Oppenheimer star Matt Damon revealed that he 'fell into depression' while shooting one of his movies.

Speaking to to Jake's Takes, the 52-year-old opened up about the unnamed flick.

"Without naming any particular movies... sometimes you find yourself in a movie that, you know, perhaps might not be what you had hoped it would be, and you're still making it.

"And I remember halfway through production and you've still got months to go and you've taken your family somewhere, you know, and you've inconvenienced them, and I remember my wife pulling me up because I was I fell into a depression about like, what have I done?"

Fortunately, however, his wife stepped in to pull him out of his funk, and he managed to get the film done.