The Usual Suspects actor del Toro plays martial arts instructor Sergio, who comes to Bob's help when he's under threat.
He explains that the film "says something about its time" but "it's also entertaining, fun and has a lot of heart".
Del Toro was most excited about having been able to work with DiCaprio, who he has "admired and wanted to work with for many years".
"Leo and I are from the same class if Hollywood was a university - I've met him many times and then finally we got a chance to work together.
"It's a dream come true and he's very funny in real life and in the movie."

