Colasanto was preparing to retire when the role of Coach Ernie Pantusso was offered to him on "Cheers". Coach would become his best known role. By the third season of "Cheers", Colasanto's health had seriously deteriorated. His fellow cast members noticed his weight loss, but Colasanto kept the severity of his illness secret. Shortly after the Christmas holiday in 1984, he was admitted to a local hospital for water in his lungs. Co-star Ted Danson later said Colasanto had difficulty remembering his lines during production of the season.