Colin Irwin proved an able deputy for Alan Hansen or Phil Thompson at the centre of defence or for Alan Kennedy at left-back.
Liverpool-born Colin came through the junior ranks at Anfield and made his league debut at home to West Bromwich Albion on 25th August 1979. A promising start continued in the next league match with a headed goal at Southampton, even though Liverpool lost 2-3. But after starting against Dinamo Tblisi in the beginning of October, Colin lost his place and didn't feature in the first-team again until six months later in April. In 1980-81 he made a further 30 appearances but this was the last season that he featured as a first-team player for the club.
When Mark Lawrenson arrived at the club in August 1981, he was surplus to requirements and he joined John Toshack's Swansea. Irwin was made captain, but a knee injury forced him into retirement at age 26 in 1983.
When Phil Neal was appointed as Bolton's player-manager in December 1985 he added Colin Irwin to the coaching staff as the new first team coach. He remained with the club until the end of the 1986-87 season.