The cast and crew of Cheers were badly shaken when Nicholas Colasanto, who played “Coach,” died from a heart attack in the midst of the show's third season. To replace Colasanto, the network wanted a younger character who was similar to “Coach." As Cheers' co-creator Les Charles explained to The Hollywood Reporter, “We settled on a Tom Sawyer/Huck Finn type from the Midwest. We cast the role and then our casting director said there’s someone you should look at.”
That someone turned out to be 23-year-old Woody Harrelson. The actor impressed during his audition particularly well - he actually cried when his character was told of “Coach's” death. As Les Charles commented, “Ted [Danson, the series' star] says to me, ‘I know the other guy is on-the-nose but there’s something different about this guy.’ He had this intensity and so he was our guy.”
But that didn't mean everything went smoothly once Harrelson joined the cast at the beginning of Season 4. As Cheers' co-creator/director James Burrows recalled to GQ, the actor's age and athleticism made some of the other actors get in their feelings: “In the first episode, [Harrelson's character] leaps over the bar, and that p*ssed Teddy [Danson] off: ‘This young whippersnapper…’ Teddy started going to the gym.”
Danson disagreed, sort of, although he admitted Harrelson had to pass a series of challenges to be accepted:
I don't know if I went to the gym, [but] Woody is 24, and at that point I was like 37, which is when you realize you're no longer 24. So in walked Woody, who was instantly great, but offstage, it was [all] testosterone. There was a half-court [on the lot], and the guys used to play basketball right before the show. We took him out to give him a lesson, and he kicked our *sses. All right, we'll arm-wrestle. I still have, like, tendinitis in my elbow. He was just wiping the floor with me. John, who has good, strong legs, leg-wrestled him. Woody cleaned everybody's clock in everything. Then we got less physical and went to chess, and he whipped our *sses with chess. I didn't have a brother, so Woody became my brother. And brothers can be incredibly competitive and knock the s*** out of each other, but they know they won't cross a line. I loved him.