He told HollywoodLife.com: “He just seems like a bright and sensitive kid.”
While Guy, 45, has starred in movies including 'The Kings Speech','Memento' and the upcoming 'Iron Man 3', he doesn't plan to offer Robert any advice.
Asked if Robert is impressed by his career, Guy said: “Um I don’t know, hopefully he thinks so! I think it’s about collaborating and all getting on the same page. It doesn’t matter how experienced or inexperienced someone is, you hopefully just all understand each other and understand you are all on the same film together.
While Robert is currently busy with his acting career, he recently admitted he loves traditional British pubs and aspires to one day own one in London.
He said: "I would love to own a pub in London at some point...I wouldn't want to buy a pub that was all trendy and done Gastro style food, I just want a real working men's pub.
"I probably wouldn't even go public that I owned it. I wouldn't want it to become the sort of place people went to spot celebrities. I just want it to be a real pub where men discuss the issues of the day.
"Men putting the world to rights over a few pints puts the Great into Great Britain; we have to fight to keep that."