Paul Pogba's return to the Manchester United squad has been delayed after the midfielder called in sick.
The French international has been missing more than two months with a foot injury, and has now suffered another stroke after being struck down by illness.
– ESPN Premier League Fantasy: Sign Up Now!
– WAS in the Premier League: Ultimate guide
– When will the transfer window open again?
– Premier League Winter Break: Everything you need to know
Manager Ole Gunnar Solskjær remains hopeful Pogba may be able to make his comeback before the end of the year, but the recent setback will rule him out on Wednesday night's Carabao Cup quarter-final with League Two Colchester United at Old Trafford.
"He is sick of all things now," said Solskjær. "He's been gone for two or three days – probably three days – so it's not favorable. It probably put him back pretty much.
"As I've said so many times, Paul is a top, top player that we want to see his best football at Man United.
"We just need to get him in shape and match. It could be half an hour, 45 minutes, 60 minutes, 90 minutes – who knows, the first game. We're working hard to get him back, but now he's sick."
United will face Colchester, ninth in League Two, and want to extend their unbeaten run to six. The Carabao Cup is down to Solskær's priority list while trying to lead his team back into the Champions League, but the Norwegian insists he will not waste the chance to win the first cup of his reign.
Harry Maguire, Victor Lindelof, Aaron Wan-Bissaka, Scott McTominay, Daniel James and Marcus Rashford all started in the last round against Chelsea, and Solskjaer prepares to pick another strong team despite facing a trip to Watford at Sunday.
"Any player or any team – and for us now it's a good team to build – will benefit a lot from winning a trophy or coming to a finals," Solskajer added.
"Of course it's important to win it. Now we have a chance to get into the semis, so for us this game is a big one.
"We showed that of the team we set out against Chelsea, that we take this seriously.
"Even though we had a difficult spell in the league, it was still important for us to create that momentum and faith in the players. We certainly hope to make it to the finals."