Joining movie legends Sylvester Stallone and Robert De Niro in Warner Bros.’ new comedy “Grudge Match” are three character actors who are at the peak of their game. They are Oscar-winner Alan Arkin (“Little Miss Sunshine,” “Argo”), Kevin Hart (“Little Fockers”) and Jon Bernthal (TV’s “The Walking Dead”).

That was just the beginning of what producer Bill Gerber calls “a fantastic cast.” He says, “The great thing about this movie is we got every first choice that we went after for each role.”

   

In “Grudge Match,” De Niro and Stallone play Billy “The Kid” McDonnen and Henry “Razor” Sharp, two local Pittsburgh fighters whose fierce rivalry put them in the national spotlight. Each had scored a victory against the other during their heyday, but in 1983, on the eve of their decisive third match, Razor suddenly announced his retirement, refusing to explain why but effectively delivering a knock-out punch to both their careers. Thirty years later, boxing promoter Dante Slate, Jr., seeing big dollar signs, makes them an offer they can’t refuse: to re-enter the ring and settle the score once and for all.

Kevin Hart: It is Hart’s character, Dante Slate, Jr., who is the catalyst that sets the story into motion. Hart was perfect for the role of the fast-talking son of the flamboyant, late boxing promoter Dante Slate, Sr. Dante Jr. didn’t inherit any money from his father, but he did inherit his famous name—and hustler instincts.

Kevin Hart says, “What made me say yes to the opportunity to work with these legends? It was a no brainer: Robert De Niro, Sylvester Stallone, Alan Arkin, Kim Basinger. Look at the company I’m in. And I’m watching ‘Rocky’ fight ‘Raging Bull.’ What movie fan, what boxing fan, what actor is not going to want to see that, or be part of it?”

Alan Arkin: Director Segal says Razor’s relationship with his longtime friend and former boxing trainer, Louis “Lightning” Conlon, played by Arkin, was adjusted to nurture the father-son elements. The director, who had worked with Arkin on the 2008 film “Get Smart,” reached out to the actor to see if he would be interested in the role.

Surprisingly, during his 50 years as an actor, Arkin had never met nor worked with either De Niro or Stallone before. “It’s always a surprise. Every time I think I know somebody from looking at their work twenty times, I end up having my mouth down to my knees. I had no idea what to expect, working with icons like Sly and Bob.”

The veteran actor was duly impressed. “I’ve never seen anybody work so hard in my life,” says Arkin about Stallone. “He’s 150 years old,” he jokes, “and he doesn’t stop! He just doesn’t stop.”

Stallone loved working with Arkin, whose stories and jokes kept him laughing on set and off. “Alan Arkin can be hysterical with just a look, but when he talks he’s even funnier,” says Stallone. “He’s such a talented, intelligent, interesting guy. I wish we could record what we talked about away from camera. I get his humor, he gets mine and we’re just shameless. We have fun. If you got nothin’ nice to say about anybody, sit next to us.”

Jon Bernthal: As Kid struggles with his diet and workout routine, he quickly finds no one at the Killshot Gym believes in him. No one is really helping Kid, until a young man comes in and starts offering some advice. When he introduces himself, he tells him, “I’m your son.”

Actor Jon Bernthal reveals that at first, the filmmakers “weren’t exactly sure about what they wanted from BJ. Did his estrangement from his father mean that he couldn’t be like him? I thought it would be interesting to put energy into having BJ be the same kind of a guy as Kid, with the same sense of humor and aggression, and the same way of handling himself. But the fundamental difference between these characters is that, where Kid had a son and bailed, BJ sticks around and raises his son on his own. That’s the role of his life, being a father, and it’s something that he believes in very much.”

BJ proved to be the film’s only casting search. Not only did the actor need to resemble De Niro, but the character had some of the most dramatic scenes in what was otherwise a comedy film.

Gerber discovered Bernthal while staying in Washington, D.C. and visiting a hotel gym. As he tells it, while passing by a table, the cover of one of the city’s local glossy magazines caught his eye and he thought casually, “‘It’s Robert De Niro in ‘Raging Bull.’ But then, I looked closer and realized it wasn’t. And not only did Jon look like a young De Niro, he’s a really great boxer. He’s been a revelation. It was a real score to find Jon.”

Bernthal says he was aware of the familiarity. “I had heard a few times before shooting that I looked like him, and I’m just glad the powers that be agreed.”

Opening across the Philippines in Jan. 15, 2014, “Grudge Match” will be distributed by Warner Bros. Pictures, a Warner Bros. Entertainment Company.