Barring an unfeasible Celtic comeback, Artmedia Bratislava, the previously unheralded champions of Slovakia, will eliminate the Hoops from Champions' League contention at Parkhead on Tuesday, having established a 5-0 first-leg lead on Wednesday night, an occasion that Strachan, 48, described as the worst in his 33 years in football.
Strachan had made it clear that his priority is the Scottish title, in a debut campaign that starts with a trip to Motherwell tomorrow. But the magnitude of the Bratislava débâcle cannot be brushed aside. It casts doubts over Celtic's ability to give Rangers a run for their money, raises questions about Strachan's future before the domestic season has even begun, and it leaves the green side of this city not only strapped for excuses but stripped of vital income, too.
Reaching the knock-out stages of the Champions' League would be worth £10m or more. Losing before the third qualifying round will mean no European football at all, not even a place in the Uefa Cup. Their fans are used to not being involved in Europe after Christmas. Being all but dumped out before the domestic season has even started is a new low.
Strachan would have known that even before he scanned yesterday's newspapers. If he dared.
"Strachan's worst nightmare", said one back-page headline. "Gord Awful", "Shameful" and "Brats 5, Prats 0" were among the others. The defeat was Celtic's heaviest European loss in the club's history. It was their worst competitive result for 42 years, since losing 6-0 to Kilmarnock in a league match in 1963.
The backlash started before the final whistle in the Tehelné Pole Stadium. Some of the travelling fans - who witnessed an away draw at Barcelona as recently as eight months ago and a Uefa Cup final against Jose Mourinho's Porto two years ago - were already calling for Strachan's head.
They were being echoed on supporters' message boards yesterday. "If we don't get a result at Fir Park this weekend, Strachan will find it impossible to carry on," one message said. Another suggested that anything less than a 6-0 win over Motherwell will result in Strachan being greeted for his first home game - against the Slovaks - by 60,000 baying critics.
What went wrong on Wednesday? And what, if anything, can Strachan do to reverse what he has admitted is the worst possible start to his management career in the country of his birth?
The blame for the rout is simple enough to apportion. Celtic were undermined by Chris Sutton going off injured after an accidental clash with his team-mate Neil Lennon in the 14th minute that left him with a fractured cheekbone. But they were sunk by woeful defending, not least by the centre-halves Bobo Baldé and Stan Varga, although the full-backs Mo Camara and Paul Telfer were also culpable for poor positioning and upfield marauding respectively. And they were hamstrung in attack, where John Hartson and Maciej Zurawski suffered through lack of service.
Strachan also decided, at 2-0 down, to chase the game by playing three strikers. One man's swashbuckling approach is another's lack of nous at this level. The ploy backfired and his side conceded three more goals. Strachan's only previous European managerial experience was a two-leg defeat to Steaua Bucharest while at Southampton.
The wider perspective of the defeat is that Strachan had already overseen four friendlies without a win, three of them goalless draws against Fulham, Leicester and Leeds, and the other 2-2 against Sporting Lisbon. If these results may not necessarily have suggested a lack of class in a squad in a state of flux - seven first-teamers have departed over the summer, including the club captain, Jackie McNamara, and seven players have been signed - then they sounded alarm bells at a lack of strength in depth.
Strachan cannot be held responsible for an ageing side and scarce resources. His newcomers - the permanent signings Camara, Zurawski, Telfer, the defender Adam Virgo and the Japanese playmaker Shunsuke Nakamura, and the loan signings Artur Boruc, a goalkeeper, and the striker Jérémie Aliadière - were gained for an average of less than £1m each and may prove canny shopping, if and when they settle.
But Strachan does not possess the trophy-winning credentials of his predecessor, Martin O'Neill, who had won silverware at Leicester. Nor, under the most critical analysis of his achievements, has he come close to maintaining either of his previous clubs, Coventry and Southampton, as genuine contenders. His time at Coventry was spent flirting with relegation and then succumbing to it. And his more than two years at Southampton are too often viewed through glasses that have become rose-tinted by the warm, witty, sabbatical-era Strachan on the Match of The Day 2 sofa.
Yes, he led the Saints to their best-ever Premiership finish of eighth in his only full season there, in 2002-03, and reached the FA Cup final the same season, losing to Arsenal. But it is little remembered that he won only two of his final 10 Southampton games before he stepped down, or that the famous Cup run involved beating only one top-flight side - Tottenham - on the way to Cardiff.
Another echo from his Southampton spell could return to haunt Strachan tomorrow in the shape of Scott McDonald, whom Strachan released from St Mary's as a 19-year-old striker two years ago. Now with Motherwell, the Australian shattered Celtic's title hopes with two goals against them in the final two minutes of last season, and he would relish adding to Strachan's agony at Fir Park.
Strachan has accepted that all his managerial career has been a fight to stay up, and now the emphasis is on winning, not surviving. Yet never has he needed a backs-to-the-wall mentality as much as now. In May his new assignment among the Old Firm was exciting, an honour, a prospect to relish. On Wednesday night, it suddenly got serious.Reuse content