The two teams have lost a combined 39 times in the Premier League, with 20-time champions United an embarrassing 16th in the table and Spurs 17th, a single spot above the relegation zone.

Yet one of them will be celebrating at the final whistle at the San Mames stadium -- not just a European trophy but a financial windfall worth potentially upwards of £100 million ($134 million).

Ruben Amorim, in his first campaign at Old Trafford, knows that victory will not solve United's long-standing and deep-rooted problems, but he admits it would change the mood.

"We have bigger things to deal with than that, to put this club back to the top," the 40-year-old said on the eve of the game in northern Spain.

But he added: "(If we win) people will look at our team in a different way, because winning a European title is really important."

The former Sporting Lisbon boss was keen to stress that Champions League revenue is not pivotal to United's future due to the size and pulling power of the club.

But football finance expert Kieran Maguire believes it is, in monetary terms, "the most important match in the club's history".

The huge cash windfall from various revenue streams would be a major boost for United, who are struggling to balance the books, providing vital funds for a squad rebuild.

- Postecoglou exit? -

The Portuguese manager's job appears safe whatever the result, even though United are destined for their worst league finish for half a century.

But many observers believe Tottenham boss Ange Postecoglou, 59, is heading for the exit door regardless of whether he ends the club's 17-year trophy drought.

"I've said to the lads from day one, nothing is guaranteed in life, nothing is guaranteed in sport," said the former Australia and Celtic coach.

"You've just got to try and make sure you take every opportunity before you and that's what I've done my whole career."

Postecoglou, in his second season at Spurs, feels he has unfinished business in London and believes winning the Europa League could be a "turning point" for the club.

"Until you actually do it, then you're fair game for people to say, 'Well, you've always kind of fluffed it on the big stage'," he said earlier this month.

Tottenham, who have not won silverware since the 2008 League Cup, have won the Europa League twice, in its former guise as the UEFA Cup, but not since 1984.

The game itself -- the sixth all-English final in European football history -- is too close to call.

Spurs have beaten United three times this season -- twice in the Premier League and once in the League Cup.

But three-time European champions United, chasing a first European triumph since the 2016/17 Europa League, have recent trophy-winning pedigree, picking up the League Cup and the FA Cup under former manager Erik ten Hag over the past two seasons.

The only league matches either club have won since February 2 have been against sides who are heading down to the Championship, or each other.

Yet they have found a way to keep winning in the Europa League.

United, the only side unbeaten in continental competition this season, reached the final with a 7-1 aggregate win over Athletic Bilbao, denying the Spanish side a fairytale final in their own stadium.

Tottenham waltzed past Norwegian champions Bodo/Glimt 5-1 on aggregate.

United boast the standout player in captain Bruno Fernandes and the trophy-winning nous of Casemiro, who won five Champions League titles with Real Madrid.

Postecoglou confirmed on Tuesday that midfielder Lucas Bergvall would not be fit to face United. James Maddison and Dejan Kulusevski are also out.