Since his arrival from St. Johnstone in the summer of 2004, Mark has done well for Saints in the defensive midfield role. He is one of these players who's presence is only noted when he is missing from the team.
As well as picking up three medals this season (he played and scored in last night's Reserve League Cup triumphy), he also won the Scottish Cup with Kilmarnock in 1997.
His decision to retire is perhaps surprising when you consider that Saints boss Gus MacPherson wanted to keep him for next season. He has also done well as a coach for the reserves.
Best of luck in the future Mark, and thanks for all your help!