Louis van Gaal could rest Manchester United players in the "red zone" for the FA Cup third-round clash with Sheffield United.
Jesse Lingard is available after overcoming a hamstring injury but Adnan Januzaj, who was recalled from his loan at Borussia Dortmund on Thursday, is not fit enough to play.
Antonio Valencia (foot), Luke Shaw (leg), Marcos Rojo (shoulder) and Phil Jones (ankle) are out while Ashley Young is likely to be rested.
"A lot of players are in the red zone," said Van Gaal. "Young was back in training this week. He is not injured, he is overloaded and in the red zone.
"More players are in the red zone and we have to decide if they can play against Sheffield United or not.
Lingard has been out since the defeat at Bournemouth in December but could return to face the Blades.
Matt Done could return for Sheffield United after a hamstring injury, and manager Nigel Adkins is relishing the challenge ahead.
"I can't wait," he said. "The Theatre of Dreams, third round of the FA Cup, Manchester United v Sheffield United - it's all to play for.
"There's three results on offer, two of them we will be happy with. You look at them and they're fifth in the Premier League and we're eighth in League One. There's a gulf, right?
"But it's the FA Cup, it's the beauty of it, the drama of it and who knows? On any given day it has been proved that someone can win and why can't it be us?"
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The Blades faced United in three successive seasons in the cup between 1993 and 1995, beating their opponents in the first of these duels before bowing out in third round ties in each of the following campaigns.
Manchester United have lost once in 36 FA Cup ties against lower-ranked sides - against Leeds United at Old Trafford in the third round in January 2010.
Sheffield United have an excellent recent cup record against higher-ranked opponents, winning five of their last six ties (L1).