In the movie, which opens Friday, Denzel plays Sam Chisolm, a bounty hunter and the leader of the group. "Oh, man, I love Denzel," Pratt, 37, said.
He added: "Denzel's a legend and a great human being. We had a good time working together. It's rare you get a chance to work with somebody who's a two-time Oscar winner. He's just decorated. Like I said, he's a legend. ... It is a bromance, yeah."
Pratt also talked about his upcoming superhero film, "Guardians of the Galaxy Vol. 2," which is set to be released in 2017.
"Marvel's going to get mad, but I'll tell you everything," he joked. "It picks up a couple of months after the events of the first movie [in 2014] and all the characters [are] back. Kurt Russell's also going to be in part two and the soundtrack is off the chain. I can't say much, but it's going to be the greatest spectacle movie of all time. I don't want to oversell it."