‘Shrinking’ Creator Reveals How He Got Michael J. Fox for Multiple Episodes (Exclusive)

Michael J. Fox is marking his return to the small screen — and he already “had to come back” for more.

Shrinking co-creator Bill Lawrence caught up with PEOPLE at the Michael J. Fox Foundation’s A Funny Thing Happened on the Way to Cure Parkinson’s Gala in New York City, on Nov. 15, where he explained how he encouraged the Family Ties alum to appear in more than just one episode of the Apple TV series.

Fox, 64, was announced as a guest on the forthcoming third season of Shrinking back in October. As Lawrence, 56, explains, he “really embraced playing a patient with Parkinson’s” in the episodes.

“It’s not a simple, preachy role. He’s a wise-ass and as acerbic as he’s always been, and he’s kind of a really key part of the first episode, and he had so much fun and we had so much — he made the mistake,” Lawrence, who previously worked with Fox on Spin City, says. “He did the first [episode] of the year that’s on in January, and he said, ‘That was so much fun. I’d do it again.’ ”

He adds, “And around me, if he ever says anything like that out loud, I’m like, ‘Oh then come back in two weeks.’ So he had to come back again.

Fox previously spoke with PEOPLE in October about his guest arc, which sees the Emmy winner share screen time with Harrison Ford — who plays a therapist with Parkinson’s, the neurodegenerative disease Fox was diagnosed with in 1991.

Fox said he made a call to Lawrence after watching the show. “I said, ‘You did a show about Parkinson’s, and you didn’t call me?’ And he said, ‘Oh, you want to do it?’ And I said, ‘I’d love to do it,’ ” Fox said.

“So he said, ‘Let me think about it, see what I can do.’ So he went to work on it and came up with this concept, it’s really good,” Fox added.

He added, “It was the first time ever I get to show up on set, and I didn’t have to worry about am I too tired or coughing or anything. I just do it. It was really good, because for the moments when I say, ‘I’m not going to be able to do this,’ then I say, ‘Well, I’ll just deal with how I can’t do it in the scene.’ And you get through it.”

Jeff Daniels will also be joining season 3 of the comedy, which was created by Jason Segel and Brett Goldstein, alongside Lawrence.

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Shrinking season 3 premieres on Jan. 28. Seasons 1 and 2 are currently streaming on Apple TV.