UEFA Cup fourth round, second leg: Martin O'Neill's touchline agonies after his side's Champions League campaign had evaporated were this season's picture of pain in football.
Last night, the Celtic manager's downbeat demeanour might have prompted witnesses to think he is steeling himself for similar disappointment.
Barcelona have been roused anew under Frank Rijkaard, nine successive wins putting them in the La Liga's third position.
"Barcelona are one of the form teams of Europe, playing better than anyone in Spain at the moment," said the Irishman.
"Had we played this fixture 13 weeks ago, who knows? But that's not to be. My disappointment if we are beaten would relate to our performance.
"If you tell me we can play poorly and get through, I'd take it. But I doubt that'll be enough. We have to play very, very well, be very vigilant to get through this.
"They've too many top-class players and we definitely need a goal. Even that might not be enough."
If O'Neill is daunted, just a season after leading Celtic to the UEFA Cup final, the effects of the last week should have soothed his fears.
Chris Sutton returns after an ankle injury that kept him out of the first leg, and Stanislav Varga should be present to marshal a defence missing Bobo Balde and the goalkeeper Rab Douglas.
Celtic's 1-0 lead may look as fragile as their patched-up defence, but O'Neill's tactic could be to gnaw away at Barcelona complacency. Their youth team and strikers' coach Hristo Stoichkov said yesterday his side would win 4-0, the sort of prediction that has cost braggarts dear in previous meetings with Celtic.
Garry Flitcroft claimed "it was men against boys" in the UEFA Cup second round, first leg before Celtic's completed a 3-0 aggregate win over Blackburn last season. Celta Vigo's former coach Miguel Angel Lotina, too, made such a boast after losing 1-0 in Glasgow, one that appeared all the more hollow for the Spanish side's failure to progress.
If Stoichkov's prediction is to prove correct, Barcelona must improve on their failure to hit the target even once from any of their seven shots in the first leg.
Shorn of the suspended Javier Saviola and the injured Patrick Kluivert, that task has been rendered all the trickier.
PROBABLE LINE-UPS
BARCELONA (4-2-3-1): Valdes; Reiziger, Puyol (or Marquez), Oleguer, Gabri; Xavi, Cocu; Quaresma, Ronaldinho, Overmars; Luis Enrique.
CELTIC (4-4-2): Marshall; Agathe, Varga, Kennedy, McNamara; Lennon, Petrov, Pearson, Thompson; Sutton, Larsson.
