Celtic's 5-0 thrashing by Artmedia Petrzalka in the second qualifying round of the Champions League was the Glasgow club's heaviest defeat in European competition.
Gordon Strachan is inexperienced in Europe as a manager
Former Celtic player and assistant manager Murdo McLeod tells BBC Sport what he believes led to such a disastrous result.
Most Celtic fans had already concluded that the central defensive pairing of Bobo Balde and Stan Varga was not working.
They had looked dodgy in pre-season friendlies.
So to go into a European tie with that partnership was asking for trouble.
INEXPERIENCE IN EUROPE
If you look at Gordon Strachan's summer signings, none of them are big names. Hopefully, they will eventually prove to be astute acquisitions.
But most of them would have been playing their first games in Champions League football, while Paul Telfer was only signed a couple of days before the tie.
Strachan himself is inexperienced at that level and perhaps panicked a bit by going to a three-man attack after Celtic went 2-0 down.
When you are 2-0 down in Europe, you are never out of it and there would always have been a chance of overcoming such a deficit in front of a packed Celtic Park in the second leg.
Getting five goals back is just about impossible.
LACK OF FIREPOWER
Celtic, who lost Craig Bellamy from last season, had failed to score many goals during pre-season and that lack of threat up front continued in Bratislava.
Even if you are 3-0 down in a European tie away from home, one goal can bring you back into it.
Away goals are vital, but Celtic squandered their chances in Slovakia.
POOR TEAM SPIRIT
Strachan's predecessor Martin O'Neill always looked after his players, financially and otherwise, and that helped build a great team spirit.
It also meant that he got more out of players than he might have otherwise.
But half a dozen of O'Neill's squad left during the summer and there does not seem to be the same unity about the place.
UNDERESTIMATING THE OPPOSITION
Celtic fans went into this tie expecting a fairly straightforward passage into the next qualifying round and that maybe got through to the players.
Just because we do not know the names of some of these teams from eastern Europe does not mean they are not any good.
There are very few genuine minnows left in European football.
But the players inherited from O'Neill's side should have had enough experience to cope with the situation they found themselves in and help the new signings.
IMPLICATIONS FOR CELTIC
The biggest blow for Celtic from this result is financial - they are likely to miss out on £10m in earnings.
It looks extremely unlikely that they will progress in the Champions League and an exit at this stage means there is not even the Uefa Cup as compensation.
Celtic would have been looking to use the money from a European run to strengthen their squad.
But their longest away trip will now be Inverness and any additions are now likely to be of a lesser quality, which could lead to a dangerous downward spiral.
It was always going to be difficult for Strachan and his new signings to win over the Celtic fans after the recent successes under O'Neill.
Now it is going to be even more of a struggle and a good start to their domestic campaign is now essential.