He and Perry starred in 'Friends' together, where he played Richard Burke, ophthalmologist boyfriend of Monica Geller.
Speaking to USA Today, Selleck recalled a scene from an early episode of the show, where Richard, Chandler (played by Perry), and Joey (played by Matt LeBlanc) tried to imitate each other.
"Matthew had this speech pattern that I hadn't been aware of," Selleck said, sharing how hard it was to say his lines in the same iconic sarcastic cadence as Perry.
"Matt told me: 'It's a joke, Tom. It's the way he says it.' But during that whole show, I kept going up to him asking, 'Can you say it again?' and he'd do the line.
"That was his signature."
Selleck also remembered Perry's "raw talent" as an actor.
"Matthew's gone, so it's easy to say this, but it's true. I think he was the most talented of a very talented group of people," he said.
