MADRID - Manager Jose Mourinho must patch up his injury-ravaged Manchester United squad as its quest for Europa League glory faces the stiffest test yet with a semifinal, first-leg trip to Celta Vigo on Thursday.

The Portuguese manager described United's nine-match April schedule as "not human" after another disappointing 1-1 home draw in the Premier League against relegation-threatened Swansea City on Sunday.

United's schedule doesn't get any easier, with six matches to come over the next 19 days in a bid to seal Champions League qualification either by winning the Europa League or squeezing into the top four of the Premier League.

"If we beat Celta, we have the final but, in this moment, it is hypothetical," Mourinho told the United website.

"The Europa League final is on the Wednesday and we play against Crystal Palace on the Sunday. Before that, we play Southampton away, so we might be playing the final with disastrous consequences."

The English giant is without top scorer Zlatan Ibrahimovic due to cruciate ligament damage.

Meanwhile, Luke Shaw and Eric Bailly added to United's defensive woes as they join Phil Jones, Chris Smalling and Marcos Rojo on the sidelines, meaning Mourinho will need to look for emergency solutions at centerback.

Mourinho has been critical of Jones' and Smalling's unwillingness to play through the pain barrier and doesn't expect them to rush back, meaning rightback Matteo Darmian, midfielder Michael Carrick or 19-year-old Axel Tuanzebe could be called on to bolster the heart of the defense.

"That's my personal opinion; I don't think they will (be fit) but I know the players I choose will give everything. It doesn't matter if I go with Darmian or Carrick or Axel, I trust the boys," said Mourinho.

United will have Paul Pogba and Marouane Fellaini back and available, while Juan Mata could make his comeback from groin surgery after being an unused substitute against Swansea.

Celta, by contrast, has had the luxury of resting Eduardo Berizzo's preferred XI for the majority of its recent La Liga games as the Galicians concentrate on trying to win a first major trophy.

"We also know what's at stake - not only that you win the Europa League, which is huge, but you can also win a place in the Champions League," Celta striker John Guidetti told UEFA.com.

"You have dreams about that."

And the former Manchester City striker would revel in ending United's chances of winning the Europa League for the first time.

"As they say, 'Manchester is blue' - and that's how it will be when we visit there as well, because we are Celta Vigo and we will try to keep the city blue."

Former Liverpool forward Iago Aspas is Celta's main scoring threat, with 24 goals this season.

The other semifinal first leg takes place on Wednesday in Amsterdam as Ajax looks to rekindle former European glories against Lyon.

Ajax hasn't reached a European final since its vintage side, featuring the likes of Edwin Van der Sar, Edgar Davids and Jari Litmanen, lost the 1996 Champions League final to Juventus on penalties.

However, a new generation of young talent now threatens to take Europe by storm, including 17-year-old Justin Kluivert, son of Ajax legend Patrick.

"It's what Ajax stands for. We give young players dreams and opportunities," said Van der Sar, now the club's general director.

Lyon, fourth in France's Ligue 1 standings, has injury troubles as it looks to reach its first CL final.

Top scorer Alexandre Lacazette and French international Corentin Tolisso have traveled with the squad, but are both doubtful.

Agence France - Presse