Barcelona need to produce a monumental fightback on Monday to add the Spanish Super Cup to the four trophies they have already won in 2015 as they trail Athletic Bilbao 4-0 heading into the second leg.
An under-strength Barca side was blown away by the Basques on Friday as they exacted revenge for defeat in May's Copa del Rey final at the Camp Nou thanks to Aritz Aduriz's hat-trick and a spectacular opener from just inside the Barca half by Mikel San Jose.
It was the first time Barca had lost by four goals against Spanish opposition for eight years and the first time in 14 years they had conceded four times in two consecutive matches.
The European champions had beaten Sevilla 5-4 after extra time in energy-sapping conditions in the Georgian capital Tbilisi to win the UEFA Super Cup just three days prior to their trip to Bilbao.
And there is belief among the Barca squad that, with more time to prepare and back close to full strength at home, a remarkable turnaround is still possible.
"If there is anyone who can turn this around it is Barca," said coach Luis Enrique, whose decision to rest Gerard Pique, Sergio Busquets, Ivan Rakitic and Andres Iniesta from the start has been questioned.
"90 minutes at the Camp Nou. I believe," Pique posted on his official Twitter account on Saturday.
Barca believe history could also be on their side. A Lionel Messi hat-trick sparked a 4-0 win over Sevilla in the 2010 Super Cup after a similarly weakened side had lost the first leg 3-1.
Neymar and Jordi Alba are still missing through illness and injury respectively, but Luis Enrique could recall goalkeeper Claudio Bravo for his first appearance of the season in place of Marc-Andre ter Stegen.
Athletic's first-leg performance was all the more impressive as they are also missing four first-team regulars through injury.
Inaki Williams, Ander Iturraspe, Mikel Rico and Iker Muniain are all expected to miss out once more and Aduriz remains cautious.
"We cannot think that Barca in their stadium can't score four goals. They are the best and capable of doing anything."
Victory would end a 31-year barren run without a trophy for Athletic and would be particularly sweet after they lost the Copa del Rey final to Barca in three of the past seven years as well as the Super Cup in 2009.
"If we lift the Cup it will be the best night of my career," added Aduriz.