Jake Gyllenhaal on Working With Brother-in-Law Peter Sarsgaard in 'Presumed Innocent' (Exclusive)

Jake Gyllenhaal is opening up about what it was like to work with his brother-in-law, Peter Sarsgaard, on 'Presumed Innocent.'

Jake Gyllenhaal is spilling the tea on stepping into the world of television and doing it alongside his brother-in-law, Peter Sarsgaard

Talking with ET from the world premiere of his new Apple TV+ series, Presumed Innocent, on Sunday, the 43-year-old Road House actor said that as an executive producer on the show, he and his fellow EPs -- including J.J. Abrams and David E. Kelley -- had hoped to get Sarsgaard on board early on. The 53-year-old Memory star has been married to Gyllenhaal's sister, actress and director Maggie Gyllenhaal, since 2009. 

"I think it was a real wish that we'd get him when we all spoke about actors that could play that role," Gyllenhaal told ET, joking that Sarsgaard -- to the producing team -- was a "long shot," even though he obviously had "an in" with the actor. 

In the show, Sarsgaard and Gyllenhaal are anything but brotherly, though. The series -- an adaptation of Scott Turow's bestselling 1986 novel -- sees Gyllenhaal as Rusty Sabich, a deputy prosecutor accused of murdering a colleague. His brother-in-law plays Tommy Molto, a fellow deputy prosecutor who goes head-to-head with Sabich at trial. 

Jake Gyllenhaal and Peter Sarsgaard at the 'Presumed Innocent' premiere at Tribeca Festival on June 9 - Dimitrios Kambouris/Getty Images for Tribeca Festival

For the family members by marriage, the show offered a unique opportunity to bond in a way that not many brothers-in-law can say they have: acting as full-blown rivals in a courtroom drama. 

"Working every day on these scenes, though they are antagonistic, it was so fun for the two of us," Gyllenhaal shared. "There's that thing with actors that we love those scenes, you know? You always love that you act those things out and it's full of drama."

The Brokeback Mountain Oscar nominee continued, "But also, you get to bring a kind of catharsis to your own relationship. You know, there is a way of us bringing the history of us and then also at the same time just the deep respect we have for each other."

ET also spoke with Sarsgaard from the carpet of the Tribeca Festival and he shared similar praise for his brother-in-law. 

"Jake is always very intentional about what he does. He does things for -- with integrity. He's way more ambitious than I am in that respect," The Orphan actor said. "It's really nice to be around someone who really will not stop until it's what he wants it to be."

Peter Sarsgaard, Jake Gyllenhaal and Maggie Gyllenhaal in 2014 - Kevin Mazur/WireImage

Outside of their relationship being a highlight of the project, the actor told ET that he cannot wait for audiences to finally have this show in their hands.

"David Kelley and J.J. Abrams approached me with a pilot and the pilot was -- [it] made me want to know what happened next and then some," he said. "Subsequently, the second one too and then so on and so forth." 

The original story is so compelling and popular that Turow wrote a sequel to the novel, Innocent, which released in 2010 -- more than two decades after the original book came out. The book was also adapted into a film starring Harrison Ford in 1990. 

Gyllenhaal shared that it was the never-ending litany of questions and twists and turns that first pulled him in and made him want to not only produce the limited series, but star in it as well. It's his first major foray into television as a longtime film actor. 

"I thought there were so many questions set up in the first episode that I was fascinated by kind of the sort of moral high wire and also kind of tsunami that this character was thrown in," the actor said, adding that the craziness only heightens throughout the show. 

Watch the trailer for the new Apple TV+ series in the player below. Presumed Innocent premieres on Apple TV+ on June 12. 

ET also got the scoop on the freshly-announced sequel to Prime Video's Road House. The remake of Patrick Swayze's 1989 film premiered at the SXSW Festival in Austin, Texas, in March, and Gyllenhaal got a standing ovation for his performance. 

"I'm really excited, I mean, it's the first sequel that I've ever really been a part of like that and to create the world and to expand the world is pretty thrilling," he shared of Road House 2.