Marlee Matlin Is Guest-Starring on New Amsterdam : 'My Mind Was Blown,' Says Sandra Mae Frank

Peter Kramer/NBC

Sandra Mae Frank's Dr. Elizabeth Wilder is about to have to make a very difficult decision on an upcoming episode of NBC's New Amsterdam — and it won't only be because of her budding romance with her boss.

PEOPLE can exclusively reveal that Wilder's mentor will be turning up in New York City with an appealing offer... and that mentor will be played by none other than Oscar winner Marlee Matlin.

"When I learned that she was going to be on an episode of New Amsterdam, my mind was blown," Frank tells PEOPLE. "I was so excited because getting the opportunity to work with her again. I've had the opportunity four times so far, but also, as a deaf actress with a deaf character in the show, working with another actress in ASL, in our first language, without a third person interpreting or having to accommodate other people and it being Marlee is just going to be a sensational experience. It's going to feel… I feel in my element with her."

RELATED: Marlee Matlin Celebrates Deaf Culture as CODA Wins Outstanding Movie Cast at 2022 SAG Awards

Frank, 31, had been to several presentations by Matlin before they officially met when Frank was starring as Wendla in Deaf West's Spring Awakening in Los Angeles (before it headed to Broadway in 2015).

"Marlee talked to us afterward, and I was just so thankful for her support," Frank recalls. "She became a wonderful mentor after that. Then, fast forward to Broadway, where she was in the show, and I got to know her really well through that. We just continued to thrive in our relationship after that. We've done several things over the years, and she's always just been a support. I can always feel free to text her if I'm looking for support — or she'll text me once in a while for support."

Peter Kramer/NBC

As for their upcoming interaction on New Amsterdam, Frank says it "kind of feels similar to our real-life relationship."

"Her character's a doctor coming in, and we have that doctor-to-doctor medical relationship. But still, she would be the person who broke through as a medical professional and a deaf person, and so would have opened and blazed that trail for Wilder to also be able to do that. Just like as an actress in my real life, Marlee Matlin was trailblazing and opening doors and being involved at a time where opportunity was less," Frank explains.

RELATED: NBC's New Amsterdam to End with a Shortened Fifth Season: 'So Proud of This Series'

Frank, who joined New Amsterdam in season 4, said the rest of the cast wasn't too starstruck seeing Matlin walking around on set.

"They were playing it pretty cool," she says. "They were already used to me, so once Marlee got there, everything went really beautifully. The director of the episode, Andy [Voegeli], was really, really wonderful. And we have a director of American Sign Language — a dazzle — who's been with me working with the writers, looking over the scripts, and we always work together to translate those scripts."

Peter Kramer/NBC

As for Wilder's budding relationship with Dr. Max Goodwin (Ryan Eggold) following his being left at the altar by Helen Sharpe (Freema Agyeman), Frank, like many fans, had concerns initially.

"At first, if I'm being honest, I was like, 'No,'" she admits. "I literally laughed when they told me what they were doing, and I was like, 'Oh, you're not joking.' And then the more I thought about it, I understood the direction we were going. I said it was important that I see Max sign, that there has to be some sort of development in the relationship where he starts to do that. It's important to show that deaf and hearing people can be in a successful relationship, yes. But I'm not going to accommodate the lip reading and have to accommodate to that world. Wilder is a really strong person and a strong character ... and she does what I call code-switching, accommodating to that hearing environment, working with hearing patients and hearing doctors, having to educate, expose all day every day. And then coming home and then dating a hearing person, and for them not to sign, would be too exhausting as a deaf person.

"Production took that note really well, that it was important that Max understand and start learning sign language because Wilder's identity is important and I didn't want to miss that."

RELATED: New Amsterdam Star Freema Agyeman Reveals She Will Not Return for Fifth and Final Season

The timeline, too, helped Frank "like, then love" the idea of Elizabeth and Max together.

"It's not anything that happens quickly, they're really stretching this out. Each episode is technically two weeks apart, a month apart at times. It really gives time for them to build their relationship," she says. "Once I saw that, I had buy-in."

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.

New Amsterdam airs Tuesdays at 10 p.m. ET on NBC.