For Matt Damon, this was one role there was no downsizing on.

The Oscar winner recently admitted that he and wife Luciana Barroso agreed that he would take a break from acting under one stipulation: If Christopher Nolan came calling he would take the part. And it just so happened that after the deal was struck, the filmmaker called to offer Matt the role of General Leslie Groves in Oppenheimer.

"This is going to sound made up, but it's actually true," The Good Will Hunting star told Christopher and Oppenheimer costars Cillian Murphy, Emily Blunt, and Robert Downey Jr. during Entertainment Weekly's Around the Table series published July 17. "I had—not to get too personal—negotiated extensively with my wife that I was taking time off."

The Air actor, who previously worked with Christopher on 2014's Interstellar, explained that he had been awaiting the opportunity to work with the Dark Night director again.

"I had been in Interstellar, and then Chris put me on ice for a couple of movies, so I wasn't in the rotation," the 52-year-old shared, "but I actually negotiated in couples therapy—this is a true story—the one caveat to my taking time off was if Chris Nolan called."

And Matt admitted that when he and Luciana struck their deal, he had absolutely no indication that a call was coming. 

This is without knowing whether or not he was working on anything, because he never tells you," the Downsizing actor said. "He just calls you out of the blue. And so, it was a moment in my household."

Those unexpected calls from the Inception director are something his frequent collaborators have come live with—even though they can never anticipate when he'll come calling.

In fact, Cillian, who has worked with Christopher on six films, echoed Matt in noting he was also unaware the writer-director was working on another movie until the call to play the titular theoretical physicist.

"Chris' way of operating is that he just calls you out of the blue," the Peaky Blinders star recalled. "I genuinely had no idea. He said he was making a movie about Oppenheimer and he said, 'I'd like you to play Oppenheimer.' I had to sit down. It was kind of overwhelming."

Christopher himself can't help but see the excitement in the way he operates.

"It's a fun way to do it," admitted the 52-year-old. "But it means that it's very difficult to call you to go out to dinner or something. Because every time you answer the phone it's like, what's it going to be?" 

But along with Luciana accepting the terms and conditions of Chris' phone calls, Matt—who shares four daughters with the 46-year-old—also credits his wife for being a support system in his line of work.

"I do pride myself, in a large part because of her, at being a professional actor and what being a professional actor means is you go and you do the 15-hour day and give it absolutely everything, even in what you know is going to be a losing effort," Matt said in a July 9 appearance on Jake's Takes. "And if you can do that with the best possible attitude, then you're a pro, and she really helped me with that." 

Oppenheimer hits theaters July 21.