Eleven years ago a man called Dave Hill published a book concerning the sociological effect a black winger named John Barnes was having on Merseyside since his transfer from Watford to Liverpool for £900,000 two seasons earlier.

The book's title was Out of His Skin. Were Hill to be writing it today he might feel the need to alter that. Out of His Depth feels appropriate.

That is where Barnes appears to be at this moment at Celtic Park, seven months into his first job as a manager. If drawing at Kilmarnock, losing at home to Hearts and seeing Rangers lead the league by 10 points was not bad enough, Tuesday night's catastrophic defeat to first division Inverness Caledonian Thistle, again at home and in the Scottish Cup, has taken Barnes to the point where the difference between waving and drowning is debatable.

This was arguably the greatest humiliation in Celtic's 112-year history.

Crucially, the club's share price had fallen 3 per cent at the close of business yesterday, 212.5p to 205p. When the season started in August it was as high as 320p.

Celtic's last three results mean they have not won a football match this century. Their last victory was at home to Dundee United on December 18th.

Inverness, it should be remembered, were still in the Highland League five years ago. Their record attendance is 5,821. In the section in the history books where clubs list their honours, Inverness have "Scottish Cup, quarter-finals, 1996".

They can now add Tuesday night's glorious result to that list, and soon may be able to add also that Steve Paterson's side hastened the end of the risky experiment Celtic began when Kenny Dalglish rang Barnes last summer to ask if the job of being team coach at Parkhead was one he fancied.

As a man who once performed in an advertisement for a telephone company, Dalglish knows all about the benefits of talking, and as soon as he heard the Inverness score he must have been onto Barnes straight away from his holiday home in La Manga. Last night, however, Dalglish was on his way back to Glasgow for a meeting with Celtic's chief executive, Allan MacDonald, and from there, presumably, on to another one with Barnes. On the way he may have picked up the tabloid newspaper with the brilliant, scathing headline: "Super Caley Go Ballistic Celtic Are Atrocious".

Not for the first time Dalglish finds himself the pivotal player in a green triangle. But he might yet be forced into making a decision about Barnes that would scupper their friendship.

MacDonald felt obliged to issue a statement on the situation yesterday. It read: "Last night's performance was totally unacceptable to myself and to my fellow directors and was simply not good enough for the Celtic support. I am addressing this situation as a matter of urgency with our director of football, Kenny Dalglish, who is returning this evening from club business overseas. The situation will be fully reviewed on his return."

It was a terse announcement, and the phrase "fully reviewed" suggests an ominous call to Barnes will be made. Barnes himself said after the Inverness defeat: "I will not be resigning," though he then acknowledged: "If the situation does not improve by the end of the season, I won't have to consider my situation. It will be done for me."

It would seem Barnes has been told that he has until May to rectify the sense of drift, and behind the scenes other Celtic directors were letting it be known that the club is in a "don't panic" mode.

There is some boardroom support for Dalglish's role to become more hands-on, although there is a concern that Barnes's authority would be undermined by such a gesture. A legitimate response to that is that Barnes's authority has already collapsed. It was always limited, but the combination of recent results and spineless performances has further eroded what faith there was in the first place.

Ian Wright's behaviour has raised a question about the wisdom of his signing, while the revelation that Mark Viduka had a dressing-room disagreement with Barnes, Eric Black, Oliver Tebily and Jonathan Gould on Tuesday shows a worrying lack of respect for the Celtic coaching staff.

Viduka is a volatile character but he has been the club's best player this season in the absence of Henrik Larsson. It is alleged Viduka queried Barnes's tactics at half-time. A physical confrontation then occurred. Viduka did not re-appear after the interval.

"We had a bit of a problem which we will deal with internally," Barnes said. "There was a situation so there is no real point in hiding that fact. It was a serious situation. There will be meetings in the next few days."

Barnes, however, may not know the full agenda of these meetings. His severance pay might be a topic.