Join The Club
NCIS recently wrapped its 23rd season on the 2026 TV schedule, and both Sean Murray and Brian Dietzen remain the only stars who have been along for the ride since the very first season. While neither actor started on the show as a series regular, their respective characters Timothy McGee and Dr. Jimmy Palmer have become a vital part of the NCIS ecosystem. For his part, Dietzen will always give props to the late David McCallum for landing him the role of a lifetime.
In the latest episode of the NCIS: Partners & Probies podcast, which Dietzen hosts with co-star Diona Reasonover, the two spoke to Young Ducky actor Adam Campbell and took some time to remember McCallum, who passed away in 2023 at 90 years old. The late actor's Donald “Ducky” Mallard didn't appear as much in the later seasons, with the character becoming a mentor to Dietzen’s Jimmy, and their relationship off-screen was very much similar. Below, Dietzen credits McCallum for getting him a permanent spot on the show:
David was a mentor and a friend to me, obviously, but he’s the reason I’m on the show. He really is. I guest starred on the show for an episode and because the two of us had chemistry and we hit it off, the producers could see that, the network could see that, but most importantly, David could as well, he said, ‘I wanna do scenes with you.’ He actually said that to me, and that meant a hell of a lot coming from him. So we proceeded to then do scenes together for the next 18 years.
It’s pretty crazy that Dietzen was originally supposed to be in only an episode or two of NCIS, at least before the producers realized they had struck gold. The Ducky and Jimmy dynamic was definitely a highlight of the series, especially in the early years, so I’m not surprised to hear that the chemistry was instant between Dietzen and McCallum.
Even after all these years, it’s clear that those first episodes with McCallum meant a lot to Dietzen. To share something so special with someone who he considers a friend and mentor who will always have an impact on him is important. It makes me wonder just how different NCIS would have been had they not had that bond, but it’s a good thing we’ll never have to find out.
McCallum has had quite a lot of influence on NCIS, and not just with keeping Dietzen on. Dietzen previously admitted that his mentor once convinced him to request a stunt double instead of running down a hill for one scene. While Dietzen ended up not using the stuntman as he did the stunt himself, he was still paid for a day’s work, which was the whole point of hiring him, as McCallum pointed out. It was definitely a sweet gesture, and I wouldn’t be surprised if Dietzen continued to use the same trick every once in a while.
It’s unknown how much longer Brian Dietzen plans to be on NCIS, since it's been a long time, but it’s all thanks to David McCallum that he’s even still on the show in the first place. Things would have been different if Jimmy hadn’t stuck around or if he had just stayed on as a recurring character. Some things, luckily, are fate, and that includes Dietzen and McCallum’s instant chemistry. Fans can see that bond on NCIS, streaming with a Paramount+ subscription. Season 24 premieres this fall on CBS.
