Manchester United manager Jose Mourinho is looking for Phil Jones and Chris Smalling to display their commitment to the cause by returning early from injury.
The Red Devils saw their defensive ranks further depleted on Thursday when Marcos Rojo picked up a knock during the Europa League quarter-final second leg with Anderlecht.
Daley Blind was able to cover at centre-half as Mourinho’s men booked their place in the semi-finals of that competition, but he is looking for Smalling and Jones to offer him a boost by making themselves available ahead of schedule.
With both men currently sidelined, he said: "I think it's time... We have Daley Blind, who has experience in the position. And I think it's time for Jones and Smalling to be brave, to risk.
"Because for the team they have to do everything, that's the way I think, we cannot do miracles, so miracles I do not expect but we have to try to do everything to accelerate the process.
"If it was me I think tomorrow [they would return]. They cannot make miracles, they have injuries and even in a crazy mentality they cannot play Sunday.
"There are no miracles, but with a special spirit you can sooner than expected. So instead of coming mid-May you can come the beginning of May, this kind of acceleration of the process."
With Rojo added to a lengthy injury list at Old Trafford, which also now includes Zlatan Ibrahimovic, Mourinho is down to 20 players in his senior squad.
Of those, three are goalkeepers, meaning that the Red Devils are one outfield player short for an 18-man matchday squad for Sunday’s Premier League game at Burnley.