Gary Neville fears Manchester United cannot afford to rest Bruno Fernandes and Harry Maguire over the festive period after identifying them as their most important players.
Fernandes has been one of the signings of the year for the Red Devils and has been essential to their attack since arriving from Sporting Lisbon in the January transfer window.
This season he has scored 13 goals in 20 games across all competitions making him the club's top scorer, and along with Maguire, Neville labelled him as irreplaceable for Ole Gunnar Solskjaer's side.
'They are the two players who I think are irreplaceable. Fernandes is irreplaceable, they are a way off without him. He's a vital piece of the jigsaw, Neville said on his Sky Sports podcast.
'Him and Fernandes, I'm not sure they can [rest them] at this moment in time because Ole hasn't got the luxury to lose a game, unfortunately.'
Neville's has also hinted that Maguire has become an underrated figure in the Red Devils following a shaky start to the season.
Maguire, along with Fernandes, have impressed recently to take United up to third in the Premier League table and both started on Wednesday night in the 2-0 Carabao Cup quarter-final victory at Everton.
Neville added: 'Maguire, I think, you'd know if he was missing. My gut feeling is that they would miss him enormously.
'I know some people say he's not the best defender in the league, that he's not done brilliantly since he came for £80m, but he's a big presence in the heart of the defence.
'He's good on the ball, he's composed and he's good in the air. He doesn't make a lot of mistakes, sometimes he gets caught but he's a good centre-back, a really good centre-back and a big presence in that team.'
United are back in Premier League action on Boxing Day with a trip to fellow top four rivals and Maguire's former club Leicester City.