NCIS is officially in its 24th season amid the 2026 TV schedule, with Michael Weatherly returning as Tony DiNozzo. Even though he’s returned to a pretty different atmo, there are still two people there that have been around practically since the beginning. Sean Murray and Brian Dietzen have both been on the show since Season 1 as Tim McGee and Jimmy Palmer, respectively. However, I had no idea that Mark Harmon and more helped Dietzen when he first joined.
Dietzen made his NCIS debut at the end of the first season back in 2004. Not only was the show slowly gaining an audience, but the JAG spinoff signified one of Dietzen’s first big roles. And it was not easy. The actor recalled joining the procedural During an episode of the NCIS: Partners & Probies podcast, Dietzen recalled having a lot of nerves for a while:
I was very intimidated. I was very anxious. I had a lot of anxiety about going to work about NCIS. …. The way it would manifest itself would just be a little bit of cold sweat stuff, and I think swallowing my words more than I would have if I was onstage. And not maybe being my full self in front of the camera at times.
It’s definitely understandable, given the circumstances. He’s working with some very talented and well-known actors, he’s on a show that’s getting bigger and he probably didn’t know just how long he’d be remain on NCIS. I'd imagine that for an actor, joining a show that’s already established is like being the new kid in school. And, of course, with that, comes a level of pressure, because a lot of eyes can be on a new actor, as many seek to see what they can do.
And, in Dietzen's case, it's a really daunting task, considering that Jimmy has some pretty difficult dialogue to deliver, which is essentially "medical jargon." Dietzen recalled filming a Season 2 episode where Jimmy had to explain some things to the team. Co-creator Donald P. Bellisario sent down some new pages with two pages filled with nothing but medical-based text. And he didn’t have a lot of time to rehearse it, which added on to the nerves:
They said purposefully, they held them, and they said, ‘We're doing this in 15 minutes.’ And I was sitting there on my trailer steps looking at it going, ‘Oh gosh, I'm about to have a heart attack, have a panic attack.’ And Harmon's head pokes out his trailer [and he says,] ‘Brian, you need help?’ [Michael] Weatherly’s head pokes out, ‘Dietzen, you good? You want some help?’ And I was like, ‘OK, thanks, guys. Thanks.’
I love that both Harmon and Weatherly offered to help Dietzen, because I can imagine that having to learn two pages of medical jargon in under 15 minutes is not easy. By that point, Dietzen hadn’t even been on NCIS for a full season yet, so he was likely as nervous as ever to still prove that he had what it takes. And that’s exactly why Bellisario did what he did:
And I go in there, and I'm like, just trying to remember the words, and Harmon goes, ‘You know why he's doing this, right?’ I said, ‘No, I don't.’ He goes, ‘He's calling your number. He wants to see you know what you got here.’ Because it was early on when I was there. I said, ‘Well, OK, let's see if we can do this.’
Harmon and Weatherly weren’t the only ones to offer support. Pauley Perrette had taken Dietzen’s lines and taped them to the bottom of the camera. And, on that first take, Dietzen didn’t miss a single line since he was looking at the script the entire time, and he impressed the director. And that was when Dietzen realized his castmates were not just his colleagues:
That was like that moment at which I was like I thought, man, a lot of my anxiety started coming down after that because I remember thinking, ‘These people are like here for me. These people are a family here, and we want to see each other succeed, and we want to be here to support one another.’ That was a real sea change for me, a real paradigm shift.
I’ve always wondered why actors stay on a show for so long and are willing to play the same character for more than a decade. In Dietzen’s case, I can certainly understand why he comes back every season. It’s clear that the NCIS is more like a family, and I love that it’s been like that since the very beginning. It makes me even sadder knowing that NCIS has had so many cast changes over the years, but at least the support seems to be present when someone is on the show. And, now with Weatherly back on the show, I’m hopeful that he and Dietzen are paying that kindness forward.
New episodes of NCIS air on Tuesdays at 8 p.m. ET on CBS, streaming the next day with a Paramount+ subscription.
