Manchester United manager Jose Mourinho admitted that Juan Mata, Chris Smalling and Phil Jones will be out for a long time due to injury.
United were dealt another massive blow to their chances of finishing in the top four after a goalless draw against West Bromwich Albion on Saturday.
Without the injured trio, along with Paul Pogba (hamstring strain) and key striker Zlatan Ibrahimovic (suspended), the Portuguese coach saw the likes of Anthony Martial and Marcus Rashford fail to find a breakthrough.
A home game against Everton in midweek will give United the opportunity to close the gap on fourth-placed Manchester City but Mourinho will have to do it with a depleted squad.
"I think a long time [Mata's absence through injury]," Mourinho said.
"I think Mata, Jones and Smalling [will be out] for a long time.
But the manager provided a glimmer of hope when talking about French midfielder Pogba.
"Pogba I cannot say is ready for Tuesday because I don't know but Pogba is not such a long-term injury as the others."
Mourinho also refused to entertain thoughts that the suspended Ibrahimovic would have made a difference had he played against West Brom.
"I don't know," he added. "We had matches here with Zlatan that we drew [before].
"He lost a penalty in the game 2-1 [against Bournemouth], he lost chances like other people did too, so I cannot say now that if Zlatan and Mata played on Saturday, we win the game, I cannot say that."