Celtic have been forced to launch a hurried search for a new manager after Gordon Strachan quit the Scottish Premier League club.
Strachan resigned on Monday just a day after a disappointing campaign ended with Celtic surrendering the title to bitter rivals Rangers for the first time in four years - made worse by the fact Celtic at one point had a seven point advantage over their bitter rivals.
The Celtic board now need to act quickly to appoint a new boss because the new season will begin in late July with a Champions League qualifier.
A number of managers have already been linked with the job as Celtic chairman John Reid and chief executive Peter Lawwell prepare to draw up a shortlist of candidates.
West Brom manager Tony Mowbray, a former Celtic player, is among the early favourites despite Albion's relegation from the Premier League after impressing fans at the Hawthorns and former club Hibernian with his brand of football.
Owen Coyle's stock has risen considerably following his two-year spell at Burnley, who he led into the Premier League via the Championship play-offs just hours after Strachan quit.
Motherwell boss Mark McGhee has long been touted as a candidate to manage Celtic, while Dundee United manager Craig Levein is also highly regarded.
Wolves manager Mick McCarthy and Everton boss David Moyes are also both former Celtic players who have done impressive jobs in England, although both are unlikely to leave the Premier League.
Reid knows he has to make a move as soon as possible and vowed to find a manager who will reclaim the title from Rangers.
"We will now aim to appoint our new football manager as soon as possible," Reid said.
"Our aim is to regain the championship which we have dominated in recent years and restore our pre-eminent place in Scottish football.
"This is nothing less than our supporters deserve and I would like to thank our supporters and our players for the commitment they have shown during the course of the season."
Strachan was never fondly thought of by a large section of the club's support who were unhappy with the quality of the team's players and his lack of Celtic background.
But his successor will find it hard to emulate Strachan's achievements in the east end of Glasgow.
He was the first Celtic manager to claim a hat-trick of titles since Jock Stein, despite having less money to spend than acclaimed predecessor Martin O'Neill and also reached the last 16 of the Champions League twice.
The new manager's transfer budget has been hit by the lack of guaranteed Champions League football as Celtic must negotiate two qualifying rounds to reach the lucrative group stage.
Strachan insisted it was an honour to have managed Celtic but his thoughts may already be turning to a fresh challenge in England, with reports linking him with the vacant manager's position at Sunderland.
He said: "I have enjoyed my time immensely at Celtic and clearly I will be sad to leave this great club.
"As I have said before, Celtic is a special club, with special supporters.
"There is no club like it and it has been an absolute honour and privilege to be the club's manager for the past four years.
"We have done all we can to bring success to the club and we were delighted to deliver three SPL titles, other domestic silverware, as well as making some great progress in Europe.
"It is just disappointing that we did not manage the fourth championship.
"However, the players can hold their heads high in terms of what they have done for the club in recent years.
"I thank all the players I have worked with at the club and, of course, my backroom team for the backing and assistance which they have given me."