Tom Selleck on Why He Was 'Scared to Death' During 'Friends' Guest Starring Role

The 77-year-old actor played Courteney Cox's boyfriend, Dr. Richard Burke, on the hit sitcom.

Tom Selleck's opening up about why he was "scared to death" during his guest starring role as Dr. Richard Burke on Friends.

During an appearance on The Kelly Clarkson Show, the 77-year-old actor revealed that being a guest on a show is "the hardest thing." And, as a prime example, Selleck offered his experience on Friends.

"I try to relax the new actors because that's really hard, to come on a show where everybody's up to speed. It's like when I did Friends," he said. "They were up to speed." A giddy Clarkson then interjects and tells Selleck he was "amazing" as Courteney Cox's boyfriend.

"I wasn't amazing at what they call the table read," quipped Selleck. And when Clarkson asked Selleck if he enjoyed his time on Friends, the veteran actor explained why he was so nervous.

"I was scared to death," he said. "I had done Taxi a long time before, but I hadn't done a sitcom. And so, I was really nervous. Courteney helped a lot. Courteney's a big help. But that group's an incredible group of friends. They obviously became friends in life as well as on the show. And it shows. It was a wonderful place to work."

Paul Drinkwater/NBCU Photo Bank/NBCUniversal via Getty Images

Selleck, who said he was only supposed to appear in three episodes but appeared in nine, played Cox's cigar enthusiast and much older boyfriend during season 2. The couple broke things off in season 3 when Selleck's character couldn't commit to having kids. He resurfaced in season 6, just before Matthew Perry's character finally proposes to Cox's character.