Diego Klattenhoff Pulls Triple Duty: 'The Blacklist' G-Man, 'Homeland' Marine, and Yahoo! TV Instagrammer

Yahoo! TV

Diego Klattenhoff is best known for his role as Brody's marine buddy Mike Faber on "Homeland." But he'll find a whole new way to serve his country this fall: playing FBI agent Donald Ressler on NBC's "The Blacklist."

In fact, he'll be pulling double duty as a G-man in September, balancing roles as a recurring character on Showtime while working a full schedule on "The Blacklist," one of the fall's most buzzed-about new dramas, which premieres Sept. 23 at 10 PM.

[Related: 'ER' Alum Parminder Nagra Checks In to NBC's 'The Blacklist' Full-Time]

"The Blacklist" also stars James Spader as criminal mastermind Raymond "Red" Reddington, who surrenders to the FBI and offers up his bad-guy Rolodex on the mysterious condition that he work only with newbie agent Elizabeth Keen (played by Megan Boone). Klattenhoff plays her partner.

Klattenhoff and co-stars Spader, Boone, Harry Lennix, and Ryan Eggold hit the Television Critics Association press tour Saturday to promote their series, which producers were quick to distance from sound-alike feature film "Silence of the Lambs."

[Related: 'The Blacklist' Stars Talk About Secretive Pilot Script, Address the Big Burning Question]

"We are all fans of that movie and it's a great movie and we're lucky in some ways to be compared to it. But there's a big difference between the characters on our show and the characters of Hannibal and Clarice," explained writer and executive producer John Eisendrath. "Red is not a psychopath; he is someone who is more of an enigma. Is he good? Is he bad? 'What is he like?' is part of the question of the series."

Watch a trailer for "The Blacklist":

Here’s what we do know: Spader stays in character, at least when it comes to style. Red sports a distinctive derby in the pilot episode, while the actor brought along a Panama hat for Saturday's meet-the-press panel. Klattenhoff had control of Yahoo! TV’s Instagram gallery Saturday and snapped photos of Spader and his straw hat, in addition to candid shots of Klattenhoff goofing around the Beverly Hilton's hotel kitchen and getting cozy with NBC's peacock.

In case you didn't catch Klattenhoff's Instagram takeover as it was happening, we've assembled his snapshots in this exclusive photo slideshow. Check it out and be sure to follow Yahoo! TV on Instagram!