The Captain America actor co-stars with Downey Jr and Hemsworth in the ensemble superhero film The Avengers. He confessed that he was in awe at working with such big-name stars.
"I'd never seen either one of them before in their outfits," Evans said of arriving on set.
"Obviously I loved the Iron Man movies and I had just seen Thor in the theatre like a week prior, and I remember coming to set and seeing both of them suited up and just thinking, I think my initial thought was, 'God, I wish I could work with those guys'."
"And the immediate afterthought was... 'I am! I am! I'm in a suit too! I can't believe this!' So that was a really nice geek moment for me," Evans told the Associated Press.
Evans recently revealed that he hopes to make a cameo appearance in future Marvel sequels.
The Avengers - out now in the UK - opens in the US on May 4.
Watch The Avengers' UK press conference below: