Manchester United are threatening to undermine the battle to avoid relegation in the Premier League after manager Jose Mourinho confirmed he will field a weakened team in the final game of the season against Crystal Palace ahead of the Europa League final against Ajax. The 20-time English league champions edged past Celta Vigo to reach the Stockholm showcase and keep alive their hopes of qualifying for the Champions League – with all eyes now on the clash against the Dutch giants.

Marouane Fellaini's header in the first half put the hosts on course for the final, but Facundo Roncaglia netted the first of the two goals needed by the La Liga side set up a grandstand finale. The goalscorer and United defender Eric Bailly were then dismissed amid a mass brawl, and the visitors almost completed a stunning turnaround but John Guidetti missed the chance to win the tie in the final minute of stoppage time.

Passage to the final on 24 May gives Mourinho the chance to claim the third trophy in his first season in charge of United. And the ex-Real Madrid and Inter Milan boss is unwilling to compromise the fitness of his first team by playing them in the last domestic game of the campaign against Palace which comes just three days before the final in the Swedish capital.

Ajax will have over a week to prepare for their first European final for 21 years, with their Eredivisie campaign coming to an end this weekend when they go for the title against Willem II. United meanwhile still have three matches to play against Tottenham Hotspur – in the final game at White Hart Lane – Southampton and Sam Allardyce's Eagles, who are still embroiled in a relegation battle.

Jose Mourinho
Mourinho has won 11 of his 13 finals as a manager and can improve on that record in Stockholm. Reuters

Palace are four points above the drop zone with two games remaining and should they lose to Hull City this weekend are guaranteed to be involved in the shake up for survival on the last day – which could also involve Swansea City – when they travel to Old Trafford. But those survival hopes have been given a major boost with the promise that United will field a wakened team 72 hours before their season-defining clash with Ajax.

"Now Ajax thinks about the final," said Mourinho, according to ESPN. "Their league finishes on Sunday, they have 12 days to prepare, and we have three league matches to play. Hopefully Crystal Palace doesn't need the last game because in the last game I'm going to make a lot of changes and nobody can blame us because we have a final three days later. The final means an opportunity to win a trophy, to be back in the Champions League, and to end the season in the perfect way because it is the last match of the season."