For the winner of the all-English showdown in Bilbao there is the mother of all get-out-of-jail-free cards with entry to the Champions League.
For the loser, the abyss of no European soccer next year, the indignity of so many unwanted records broken, and uncertainty hanging over the futures of those who have presided over such a spectacular fall.
That's what's on the line at Estadio de San Mamés when two English soccer giants get one last shot at salvaging the season.
Long gone are the days when United dominated the Premier League and challenged the summit of European soccer on a regular basis. But even after 12 years without winning the English title, this season has represented a new low.
United are 16th out of 20 in the standings after a club-record 18 defeats in a single campaign since the Premier League began in 1992. They also are certain to register their worst-ever points total in the era, as well as their lowest finish.
Tottenham are one place below United having lost 21 times in the league - also a club record in the modern era.
Spurs - Champions League runner-up in 2019 - are aiming for a first trophy since the 2008 English League Cup.
It is rare such a major final has so much riding on it beyond the trophy itself.
Neither team has looked capable of challenging for a top-five position in the Premier League, which would secure Champions League qualification. But in a season when both teams occupy the last safe spots before relegation, they have a mind-boggling lifeline to the Champions League via the Europa League.
"We are supposed to be in the Champions League. Europa League here is not enough and you have that feeling here," Manchester United coach Ruben Amorim says. "The best way to help us get in the top in a few years is the Champions League - it's not (winning) the cup (Europa League)."
While a return to the Champions League is also enticing for Tottenham, the chance to end their trophy-barren run may be even more appealing.
Not even top-class managers like Mauricio Pochettino, Jose Mourinho or Antonio Conte could end Spurs's wait for major silverware.
It could be destiny that Australian Ange Postecoglou is the man to end the drought, having boldly predicted early in the season he always wins a trophy in his second year.
That was true at previous clubs Brisbane Roar (Australia), Yokohama F Marinos (Japan) and Celtic (Scotland), but it would be remarkable if he continued that run on the back of such a desperate campaign.
"It's not for the want of world-class players. This club has had world-class players," Postecoglou says. "It's not for the want of world-class managers. They've had world-class managers. It's something else that's going to change this club."
Postecoglou is two years into the job at Spurs and became the club's fourth permanent manager in four years when joining from Celtic in 2023.
A major trophy would put a different complexion on a season in which Spurs have dramatically fallen since he led them to a fifth-place finish in his first year.
He and Amorim have spoken of the similarities about their positions.
"I guess from an emotional standpoint and the noise around the club," Postecoglou says, "we're kind of dealing with similar things of something that is so fantastic in terms of a European run, and also something that's obviously the opposite of that, the other extreme in the league."
16°C