In 1975–76, Cormack's fourth season at Anfield, Liverpool completed another League and the UEFA Cup double. Cormack played in both legs in the UEFA Cup first round 3–2 aggregate win against his former club, Hibernian. Cormack was a regular league starter until the end of October. In the next six leagues games he made the team sheet only once, as a substitute against Coventry City. He was then named as substitute against Burnley before a run of four games in the starting line-up, including a crucial 2–0 home win against Queens Park Rangers that put Liverpool in top spot ahead of the London club. The last of those four games was the 1–0 home league win against Manchester City on 27 December 1975. Cormack scored the only goal in what was to be a landmark game for him. A long-standing underlying problem with knee cartilage materialised into an injury after the game, when the cartilage cracked. He lost his place in the team and missed the rest of the season, which included the 4–3 aggregate win against Bruges in the UEFA Cup Final, and never played again in the Liverpool first team. He was an unused substitute in the 1976 FA Charity Shield win against Southampton at the start of the following season.