Manchester United will lose £21 million in sponsorship money, if they are beaten in the Europa League final by Ajax next week and subsequently lose out on Champions League qualification.
United's 2-1 loss to Tottenham Hotspur last Sunday, means they can't finish in the top four this season.
Jose Mourinho's only hope of playing in the Champions League rests on the final in Stockholm on May 24.
The club's chief financial officer, Cliff Baty, confirmed on Tuesday that the terms of United's kit deal with Adidas, mean they will miss out on 30% of their potential £70m annual revenue, if they fail to win the game.
"It's a 30% reduction in the following year's payments," Baty told an investors' call after the release of United's financial figures for the third quarter of the financial year.
"So receipt of sponsorship next year from Adidas would be £70m if we're in the Champions League, so that would be 30% of that, so £21m reduction.
The important thing to remember about that is it's spread out over the remaining life of the contract."