Jeremy Strong’s approach to acting has his co-star worried.

On Thursday, “Succession” star Brian Cox appeared on “Late Night with Seth Meyers” and talked about Strong, who plays his son on the show, and his deeply immersive approach to acting.

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“The thing about Jeremy’s approach is it works in terms of what comes out the other end,” he said. “My problem — and, it’s not a problem, I don’t have a problem with Jeremy because he’s delightful. … He’s an extraordinary dad. He’s a pretty unique individual.

Cox continued, “But, he does get obsessed with the work. And I worry about what it does to him, because if you can’t separate yourself — because you’re dealing with all of this material every day. You can’t live in it. Eventually, you get worn out.”

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He went on to compare Strong’s approach, which involves staying in character as much as possible even when the cameras aren’t rolling, to another legendary actor.

“Like, to me, Daniel Day-Lewis got worn out at 55 and decided to retire because [he] couldn’t go on doing that every day. It’s too consuming,” Cox explained. “And I do worry about it. But the result — what everyone says about Jeremy — the result is always extraordinary and excellent.”