Irish legend Roy Keane has retired from professional football after having trouble with an injury to his hip.
The former Manchester United player made the decision to quit the sport on the advice of medical experts.
Keane said: "Having received advice from my surgeon and the Celtic doctor my only option is to retire."
Keane joined Celtic in January from Manchester United, where he won seven league titles and three FA Cups during his 12-year career there.
The Irish international signed up to Celtic in an 18-month deal, during which time he managed 13 appearances for the Hoops last season.
He added: "I would like to send the manager, staff, the players and the supporters of Celtic football club my best wishes for the future."