Manchester United are facing an injury crisis that is threatening to derail their Europa League campaign and Premier League run-in.

To secure Champions League football next season, Jose Mourinho's team either need to lift the Europa League trophy in Stockholm next month, or finish in the top four. Ideally, they would like to do both. But with a maximum of seven games remaining, United have a host of injuries to deal with.

They are set to travel to Spain for their Europa League semifinal first leg against Celta Vigo with just 14 senior outfield players available. It could force Mourinho to turn to the academy to make up the numbers at a key moment in the season.

Axel Tuanzebe

The 19-year-old was first brought into the first-team squad by Louis van Gaal last season but it didn't take long for him to catch Mourinho's eye either. Tuanzebe, who can play in defence or midfield, was involved in Mourinho's first game, a preseason friendly against Wigan in July, made his senior debut in the 4-0 FA Cup win over the same opposition in January and has been involved in the last three matchday squads.

Mourinho hinted at the weekend that Tuanzebe, the club's young player of the year in 2015, is an option for the rest of the season with centre-backs Eric Bailly, Phil Jones and Chris Smalling all recovering from injury.

"It doesn't matter if I go with [Matteo] Darmian as a central defender, if I go with [Michael] Carrick or Axel [Tuanzebe], I trust the boys, the spirit is amazing, the group is phenomenal," he told a news conference after the 1-1 draw with Swansea on Sunday.

Tuanzebe is already part of Mourinho's first-team plans. Martin Rickett/PA Images via Getty Images

Matty Willock

The central midfielder, 20, got his first senior experience when he was named on the bench for the 0-0 draw with West Bromwich Albion last month. Signed from Arsenal in 2012, he has been a regular for the Under-23s this season, scoring a stoppage time winner against Liverpool at Anfield in January.

With the energy to go from box-to-box and a good range of passing, he is considered a good prospect by United's academy staff. However, he has seen his chances of a first-team debut recede with Paul Pogba expected back from injury this week.

Scott McTominay

McTominay is the latest academy player to be promoted by Mourinho. The midfielder, 20, was included in the senior squad for the first time ahead of the 1-1 draw with Swansea on Sunday, although he didn't get on. Usually a central midfielder, he has played up front for the U23s this season to help stand-in manager Nicky Butt cope with a striker shortage.

He has also had to deal with his share of injury problems, some of which were caused by a growth spurt from 5-foot-6 to 6-foot-3 in the space of 18 months. "It takes a little bit of time to get used to it," he told the club's website in 2016. "It's not a problem, though. It's just more of the fact that my body was not ready at all."

McTominay was called up last weekend. Martin Rickett/PA Images via Getty Images

Tyrell Warren

The 18-year-old was name-checked by Mourinho in his first news conference as United manager. "The first game against Wigan is very important because I'm going to have some players I don't know very well," he told MUTV in July. "At Wigan I will be bringing guys like Tyrell Warren and Axel Tuanzebe. I don't know them well but I just trust Nicky Butt, John Murtough and the structure's judgement, obviously I'm going to work closely with them so I trust them, when they say we have a few players who, in a couple of years, can be first-team players."

Warren, who has jumped between Kieran McKenna's U18s and Butt's U23s this season, can play at full-back or centre-back.

Regan Poole

The defender already has senior experience after playing 17 times for Newport in League Two before moving to Old Trafford in 2015. He has also made his United debut after coming on as a late substitute against FC Midtjylland in February, the game during which Marcus Rashford exploded onto the scene.

The 18-year-old can play at centre-back or in midfield and came close to earning a place in the Wales squad for the European Championship last summer despite not yet making his full international debut.