The action actor revealed that co-star Sylvester Stallone encouraged him to 'have fun with it'.
According to Yahoo, Lundgren said: "Stallone let me have a lot of fun with it, and not be so stoic or serious all the time - but it was hard because I'm not known for my great comedies.
"If you're a big guy, you have to be comedic and easy-going, otherwise you're just too threatening. But it was difficult and Stallone was yelling at me and pushing me.
"I don't mind killing people or crying, but at four in the morning, when I'm burned out emotionally, don't ask me to be funny."