Jeff Bridges had no idea that his role as Dan Chase in the FX thriller "This Old Man" would pack a punch.

The actor, who stars as a former CIA spy in the series, recalled how he played many of his fight scenes while fighting another real-life battle – cancer.

"What makes me laugh, I’m doing this scene, all that fighting and I’ve got a 9-by-12 inch tumor in my body, taking those punches," the 72-year-old told The New York Times on Thursday. "But it didn’t hurt; it had no pain, so I didn’t feel them."

In 2020, the Oscar winner announced he was diagnosed with non-Hodgkin lymphoma, a cancer of the lymphatic system. "The Big Lebowski" star quickly began chemotherapy by infusion, as well as oral chemo, which prompted the tumor to shrink. But during chemotherapy, he was infected with the coronavirus. Bridges said the cancer went into remission, but COVID nearly killed him. He spent five weeks in an intensive care unit.

JEFF BRIDGES ADMITS FAN LOVE 'SAVED' HIS LIFE WHILE BATTLING COVID, CANCER

Jeff Bridges John Lithgow this old man

Jeff Bridges and John Lithgow developed a closek-knit friendship on set after "The Big Lebowski" star faced a scary health battle. (Steve Granitz/WireImage)

"[It] made the cancer look like nothing," he said.

According to the outlet, Bridges was diagnosed with cancer after production was shut down by the pandemic. By then, they had shot four of the seven episodes. Bridges’ co-star John Lithgow, who plays Chase’s former colleague Harold Harper, doesn’t share a scene with him until late in the season.

"In a sense, our working relationship unfolded the same way the series does," Lithgow, 76, told the outlet. "It was such a payoff, and it was worth waiting for."

The fellow Oscar winner noted he was eager to work alongside Bridges, someone he’d seen since he was 19 years old in the movies.

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Jeff Bridges family

Jeff Bridges, Susan Geston and their daughter. (Tibrina Hobson/WireImage)

"Both of us were having a fabulous time, but both of us were restless, wanting to get together," Lithgow explained. "Chase and Harper have such a fascinated and complex story. We were two tigers waiting for red meat."

Bridges said he was determined to be in fighting shape, both on and off the screen.

"… It was important to the story," he shared. "I had a trainer, Zach Wermers, who was my physical therapist for my illness, and we met three times a week. We had these little goals. The first one said, ‘Well, let’s see how long you can stand.’ And I stand for 45 seconds, and then that’s it. My big goal was walking my daughter down the aisle without oxygen. After I did that, and I danced with her, I said, ‘Well, maybe I’ll be able to get back to work?’ I really didn’t think I was going to be able to do it."

Lithgow said he was grateful to share the screen with Bridges at this stage in his life.

JEFF BRIDGES SAYS HE WAS 'CLOSE TO DYING' BATTLING COVID WHILE IN CHEMO FOR CANCER: 'I WAS READY TO GO'

John Lithgow

John Lithgow attends "The Old Man" Season 1 NYC Tastemaker Event at MOMA on June 14, 2022, in New York City. (Jamie McCarthy/Getty Images)

"Well, we are both old, there’s no getting around it," he said. "And to me, these are the most interesting years of my acting career. I mean, we are well cast – we’re not pretending that we’re younger than we are. To me, we’re just very lucky actors that we are still viable and hirable, and that there are still projects as complex and challenging as this that really are about age. They’re about mortality."

"There’s a thing, and I don’t know what to term it – old age adolescence?" chimed Bridges. "A thing that we’re going through, that we’ve never gone through. It’s like a weird puberty of sorts, becoming older and having different perspectives on things."

The men said that not only are they thankful to have thriving careers in Hollywood, but it has led to a new friendship.

"God, it’s really a blessing," said Bridges.

"And think what it’s like to make such a friend," said Lithgow. "I’m 76, and to stumble on this wonderful friendship at our age, it’s just great."