Manchester United manager Jose Mourinho said he feared Luke Shaw had "a big injury" after the defender limped off only nine minutes into the 1-1 draw with Swansea City at Old Trafford.
United, already beset by injuries, lost both Shaw and Eric Bailly as a late Swansea leveller scuppered their hopes of moving into third place.
Shaw looked to have suffered a knock to his ankle after just nine minutes and made his way to the touchline before being replaced by Antonio Valencia on what was only his ninth Premier League start of the season.
And United had yet another injury problem to worry about when, after 57 minutes, Bailly went down after a challenge with Llorente and had to limp off soon afterwards.
And the BBC reported a frustrated Mourinho as saying: "I think Luke Shaw's must be a big injury, because to leave the pitch after 10 minutes I am expecting a very big injury."
Bailly's injury has left Mourinho without a recognised senior centre-back, and the United manager said he did not expect Chris Smalling or Phil Jones to recover from injuries in time to face Celta Vigo in the Europa League on Thursday.
Mourinho, who could use Michael Carrick, Matteo Darmian or youngster Axel Tuanzebe in the centre of defence, told a news conference: "I don't think they [Smalling or Jones] will be fit, that's my personal opinion.
"I don't think they will but I know that the players I choose they give everything so doesn't matter if I go with Darmian as central defender, if I go with Carrick or Axel, I trust the boys."
United have Paul Pogba, Zlatan Ibrahimovic, Smalling, Jones, Marcos Rojo and Timothy Fosu-Mensah all out, while Marouane Fellaini is serving a three-game suspension after headbutting Manchester City's Sergio Aguero in last week's derby.
But Mourinho said: "The spirit is amazing, the group is phenomenal. Fellaini and Pogba will be back for that [Cleta Vigo] game, so we try with everything we have and we go again."
Earlier, the frustrated manager had said United players "can walk from the bed to the toilet and break a leg."
He added: "I feel a point is not good, but my players gave everything. We are a squad of 22 that at this moment is a squad of 12 or 13."
Mourinho said United "will keep going until the end with this attitude" and said he had "zero criticism for my boys."
He added: "We lost players and we lost points, so today was a bad day. We did not look tired and exhausted, we are tired and exhausted.
"You cannot isolate the performance out of the context. This is the ninth match of April, it is not human. The players are very tired."
Mourinho stressed that United "will give everything on Thursday" against Celta Vigo but added: "Whether we go to the final or not doesn't matter. I am really happy with the guys."
Midfielder Juan Mata, meanwhile, returned to the squad against Swansea after injury and was named on the bench.
"I prefer not to speak about Phil Jones and Chris Smalling," Mourinho said. "I prefer to speak about Juan Mata giving everything to be available. I am grateful for that."