It was a couple years ago that Michael Weatherly decided he was ready to move on from NCIS. And he was initially looking forward to taking some time off while he considered what he wanted his next professional move to be.

"I was so comfortable with Tony DiNozzo on NCIS that ... it was interesting when that seemed to have run its course. I thought maybe it's because I'm getting older and I just want to have a different experience. And NCIS wasn't the place for that," Weatherly tells TVGuide.com. "I was really just looking for a change, and I didn't know exactly what that would be. In all honesty, I didn't think it was going to be another full-order network hour drama. Simply because that schedule is punishing, and I've been doing it for the last 16 years. ... I wasn't really looking for a rest as much as something different."

But then along came Bull, a new project from Steven Spielberg's production company, co-created by Dr. Phil McGraw and Houseco-creator Paul Attanasio, and In Treatmentcreator Rodrigo Garcia attached as a director and executive producer. The show was inspired by McGraw's early career in the field of trial science (a.k.a. the art of helping lawyers select juries). Weatherly says he couldn't resist the pedigree.

Fall TV: Add Bull and more new shows to your Watchlist

"You add all that stuff together, and ... [it was] really a compelling, rich, challenging idea," Weatherly says. "So I took all of that information, all those different elements, and I sat down with Robert Wagner, who played my dad on NCIS, and I said, 'What do you think of this?' And he just stared at me and said, 'You have to think about this?' So it was kind of a no-brainer."

In many ways, Bull (Tuesday, 8/7c, CBS), is familiar territory for Weatherly. It's a procedural featuring a team of heroes who essentially try to crack a different case week after week. (The pilot even includes the same clicking-camera, rapid-fire mini montage that is used on NCIS.) Only this time Weatherly's steering the ship rather than acting as the captain's right-hand man. He stars as Dr. Jason Bull, a trial scientist who's so skilled at reading potential jurors that he can more or less decide the outcome of a trial before the opening statements are even delivered.

"He has an addiction to human behavior and figuring people out," Weatherly says. "I don't think it's a simple thing. I think he's involved in trying to figure people out because he's really trying to figure himself out on some level. In that way, I think he's very relatable and not too smart or aloof or cool. I try to make him as warm and relatable as possible."

Still, even with a great pedigree, a blessing from Robert Wagner and a fascinating character, Weatherly says that when he started preparing for the new role, he was wondering the same thing many fans are probably curious about now: whether he'd truly be able to leave Tony DiNozzo behind.

Michael Weatherly on how Bull differs from Tony DiNozzo

"I don't think Bull seems like DiNozzo 2.0," he says. "When we were first starting I thought, well, gosh, I'm not entirely sure how to build a new character. ... I thought a lot about iconoclastic, maverick characters and how they engage in the world."

To that end, Weatherly says he drew inspiration from House's titular M.D. (Hugh Laurie), as well as Marcelo Mastriani's character in 8 1/2."Guido is this director who's trying to make a picture ... but he's kind of bluffing his way through it until it can congeal and come together," he explains. "But he's surrounded by these incredibly talented people who are gonna help him do this thing. I loved that idea. ... Bull isn't so much the smartest guy in the room as he's the guy who made sure that he surrounded himself with the smartest people. And that makes him the smartest guy in the room."

The ensemble cast making up Bull's support staff includes Freddy Rodriguez (Six Feet Under, The Night Shift), Tony Award nominees Christopher Jackson (Hamilton) and Geneva Carr (Hand to God), Jaime Lee Kirchner (The Mob Doctor) and The Knick's Annabelle Attanasio (daughter of Paul).

Bull also evokes comparisons to another CBS procedural. Fans of The Mentalist will notice similarities between Bull and Patrick Jane (Simon Baker), in that both men possess a gift that may turn out to be more of a curse than a blessing. And Bull is no superhero. His flaws will become more apparent as the series goes on, according to Weatherly.

"This is the kind of show that there's a lot of layers to. I think people are going to, week after week, peel the onion that is Dr. Bull," he says. "Bull is struggling with something. We'll learn more about that as we go. ... I haven't figured him out. If I had, that would be really boring. He's a mystery to me, so I'm on the same journey as the audience in a way. But I find him troubled, human. I think he believes in people, so he's a humanist and a realist. And those two things can sometimes make you cynical. Instead of that, he's not idealistic, but he's optimistic. And I like that. I try to keep him in that zone as much as possible."

Bull premieres Tuesday, Sept. 20 at 9/8c on CBS.

(Full disclosure: TVGuide.com is owned by CBS.)