Though Dr. Andrew DeLuca may no longer be around on “Grey’s Anatomy”, actor Giacomo Gianniotti is making his return to the long-running medical drama to direct an episode.

The Canadian actor was a welcome sight on set, with Gianniotti praising his former co-stars including Ellen Pompeo, whom he tells ET Canada has been a “mentor” to him over the years.

“After this much time on a show, I can understand how it would be difficult for someone to sort of come in every day with the same amount of care and gusto and energy after all these years, and she does,” he says of Pompeo. “She cares so much about the show, she fights for all the greatest choices. She’s taught me a lot about the industry and how it works, and to me, has been an invaluable friend and resource and mentor over the years.”

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Fans said goodbye to Gianniotti’s Dr. DeLuca in the “Grey’s Anatomy” and “Station 19” crossover episode in March, when the doctor was fatally stabbed. Since then, fans have been reaching out to the actor to share how much the character has meant to them.

“It’s been amazing these past couple weeks to just, you know, feel the outpouring of love from all the fans,” he says. “I didn’t have time to respond to every single person. So if you’re listening — I read them and I saw them, and thank you so much. it means the world to know that you were impacted by DeLuca.”

Gianniotti makes his “Grey’s” directorial debut with the April 8 episode, calling it a “true to heart” episode of the series.

“Honestly, I was so happy when I got it because it was just so true to heart, a ‘Grey’s Anatomy’ episode,” he teases. “We got our medical scenes, love and romance between our main characters, and drama between our main characters, a healthy balance of inside the hospital and outside the hospital, got some great surgeries.”

“It’s just a really, really great episode and I’m really proud,” he adds.