Former striker John Hartson has called on Celtic to appoint a "strong" character as their new manager this summer.

Current boss Ronny Deila announced this morning that he would be leaving the club this summer following Sunday's Scottish Cup semi-final defeat to arch-rivals Rangers on penalties.

Hartson, speaking at his charity's golf day, said: "Celtic are going to need a little bit of surgery to that team and a manager that is going to go in and say, 'This is what I need, can we get this player, make sure we get him, I like him.'

"And a manager that will stand up and be strong in that dressing room. Whoever gets it, it is a fantastic job and it is a great club."

David Moyes is the early favourite with the bookmakers to take over at Parkhead, while former manager Neil Lennon has said that it would be tough to turn down a return.