If the Catalan giants fail to win against Bayern Munich in Germany, Benfica will only need a victory against already-eliminated Dynamo Kyiv to go through to the knockout stages.
And that scenario seems more than possible and would be the final insult in a year when everything that could go wrong for Barca has done so.
The post Lionel Messi era at Barcelona was always going to be difficult without the unique brand of sorcery provided by the little Argentine magician, yet the exit of the club's greatest ever player has only been part of their problem.
The chaotic and ultimately doomed reign of Ronald Koeman as the club's manager was part of a narrative that sees Barcelona heading into their Champions League date with destiny fearing the worst.
Recently appointed head coach Xavi (right) is keen to turn the page on the negativity that has engulfed the club in recent months, as he turns his focus to a game that could define Barcelona's season.
The last two meetings between Barca and Bayern ended 8-2 and 3-0 in the German side's favour, but Xavi says he's seen enough in two matches since replacing Koeman to believe that winning in Munich is possible.
"What makes me most optimistic is seeing the team playing in this way," said Xavi, whose side failed to seal their place in the last-16 of the Champions League after a draw with Benfica at the Nou Camp last month.
"We can go to Munich and win. The positive news is we still depend on ourselves. It is a process for us here. We have to restore the confidence of the players that score goals.
"I'm not just talking about the forwards, either, but the midfielders that arrive from deep as well. I am not here to talk about the possibility of not going through. That is not my focus.
"We need to think about the prospect of being in the next round of the Champions League and that means winning in Munich."
As Benfica have recorded a win and a draw against Barcelona in Group E, the Portuguese side will progress to the next stage of the competition courtesy of that head-to-head record if they finish level with their Spanish rivals.
So a point for Barcelona in Munich may not be enough to secure their passage to the next phase of the competition.
Yet the truth must be that their exit would be more eye-catching than it is significant this season.
They will always be one of the biggest names in European football, but Barcelona are not Champions League contenders this season and even if they beat a Bayern side that may rest some star names as they are already through to the next round as group winners, Xavi would need to produce a miracle to get his team anywhere near the final of Europe's elite competition.
Goals were never lacking when Messi was weaving his threads of gold at Barcelona, but they have struggled to find a finishing touch now that the great man has gone.
That lack of attacking power has been especially evident on their travels, with Barca scoring just seven goals in their first six away matches in La Liga this season and they have scored only twice in their five Champions League group stage matches.
"Barcelona is the most difficult club in the world to be the coach," added Xavi, who won eight league titles and was a four-time Champions League winner during his decorated playing career.
"The Catalans are very demanding and it is not enough for us to win, as we have to play well. I think we're on the right path, all we're missing is to be more daring in the three quarters of the field up front.
"In general, I'm quite satisfied with what I see on the pitch since I arrived, but I realise there is so much more to do.
"We want to force our opposition into their own half and we're achieving that, but we have to score and win games."
Even if Barcelona avoid a drop into the Europa League this season, their lowly position in the La Liga table means they face a battle to qualify for next year's Champions League.
Amid a year when very little has made sense in any walk of life, the sight of Barcelona in this dishevelled state adds to the chaos.