GLASGOW (AFP) - Gordon Strachan's long-term future as Celtic manager will be in serious doubt if the Parkhead side fail to avenge last week's defeat when they face Motherwell on Sunday.

The Parkhead side's ambition of winning three Scottish Premier League titles in a row all but vanished on Saturday when they lost 1-0 at home to the Fir Park team.

After the final whistle a sizable section of the Celtic supporters chanted their opinion that Strachan should leave the club.

Although it is unlikely the Parkhead club will catch leaders Rangers, who are seven points clear with a game in hand, the fans will at least demand their team close the gap by the end of the season.

It may seem harsh for a manager who has won consecutive SPL titles and took Celtic to the last 16 of the Champions League for the first time - then repeated the feat the following season.

However, if Celtic fail to secure a victory away to Motherwell this weekend there will be severe pressure on Strachan to resign or to be sacked.

Despite Strachan's success since taking over from Martin O'Neill he has never enjoyed the same popularity as the Northern Irishman.

Many reasons have been suggested for the lack of respect the current Celtic manager receives from the club's supporters.

The fact Strachan is not a "Celtic man" having not supported the club as a boy, his success as a player with Sir Alex Ferguson's Aberdeen in the 1980s where he regularly tormented the Parkhead side, and even the abrupt way he comes across when speaking with the media, have all been suggested as reasons for his unpopularity in the stands.

It is no surprise, therefore, that many of the names suggested as possible successors to Strachan - including Everton's David Moyes, West Bromwich Albion's Tony Mowbray and Motherwell's Mark McGhee - have played in the green and white hoops.

While Mowbray and McGhee would perhaps not be difficult to persuade to leave their current posts, Moyes is the man most Celtic fans would choose as their next manager.

At first glance, however, it would appear the Everton manager would be unlikely to leave a side who are challenging for fourth place in the richest league in the world.

Moyes, who ironically took over from current Rangers manager Walter Smith as manager of Everton in 2002, is one of the most highly rated managers in England and has even been tipped as a possible successor to Sir Alex Ferguson at Manchester United.

However, with the Man U boss showing no sign of retiring and Moyes out of contract at Everton at the end of the season, there are suggestions he may feel he has taken the Merseyside club as far as he can.

Even if Everton were to finish in the top four this season it is not a position they would be likely to maintain in seasons to come - having nowhere near the level of resources available to Man U, Arsenal, Chelsea or city rivals Liverpool.

Winning silverware, if not impossible, will be exceedingly difficult for Moyes to achieve in his current position.

In contrast, at Celtic he would be expected to win trophies every season and would also be almost guaranteed regular Champions League football.

However, it is still likely Moyes will remain at Everton if the board guarantee him the transfer budget he believes is required to match his own ambitions for the Goodison club.

Celtic will be without midfielder Scott Brown on Sunday - as he starts a three match suspension - while Motherwell pair David Clarkson and Bob Malcolm are also suspended.

Fixtures (1300 GMT unless stated)

Sunday

Motherwell v Celtic