John Hartson has called on the club's board to appoint a "strong" manager as Ronny Deila's successor.

The Celtic Park hierarchy have started the search for the Norwegian's replacement after announcing Deila will depart this summer after the final five games of the campaign.

Confirmation of Deila's exit comes in the wake of Sunday's Scottish Cup semi-final loss to Rangers and former Celtic forward Hartson believes the new man will have to perform some "surgery" to the team.

Ahead of his foundation charity golf day, the former Wales international told STV what type of character he thinks is required for the job.

He said: "A strong manager, somebody to go into the board and say, 'We need money, we need this player, can we go and get him?'

"We know we are not in the era of when Martin O'Neill went out and spent £20 million on myself, Chris Sutton, Alan Thompson and Neil Lennon.

"You can't do that in terms of the funds, where the club is and the money that comes into Scottish football.

"But 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."

Celtic are eight points ahead of Aberdeen at the top of the Ladbrokes Premiership with five post-split fixtures remaining. Hartson is hoping Deila departs after securing his second and the Hoops' fifth consecutive title.

"I am delighted that they have done it the way they have done," he said.

"I think they have shown a bit class in terms of allowing Ronny to manage the team to the end of the season.

"I am glad that Ronny will get his day in front of the fans to lift the title - if Celtic can get over the line of course.

"He will leave on the back of two titles and he can be proud of that, but in the very big games, a couple of semi-finals this year, the big European qualifiers, the Europa group stages, there have been too many failures. I think it is the correct decision."