Sir Alex Ferguson has revealed that Wayne Rooney will miss Manchester United's Europa League match against Ajax with a throat infection.
The striker missed training on the eve of the game and it was thought he could be rested for the visit of the Dutch side to Old Trafford.
It has now emerged that Rooney is struggling with an illness and will not be fit for the European encounter.
Ferguson will hope he has recovered in time to be available for Sunday's Premier League fixture at Norwich.
The Red Devils are well placed to progress to the last 16 of the Europa League after winning the first leg of their clash with Ajax 2-0 in Amsterdam last week.
Ferguson may decide to rest a number of key players on Thursday to keep as many members of his squad fresh as possible ahead of the run-in to the end of the season.
"Wayne is out tomorrow," said Ferguson. "He has a really bad throat.
"There were traces of it in Amsterdam and we gave him some medication but it got worse.
"He has been in bed over the weekend and came in today for the first time and we are trying hard to get him right for Sunday."
Young French midfielder Paul Pogba may also come into contention, although it seems more likely the 18-year-old, whose contractual position remains unresolved, will be on the bench.
"It is possible we could give Pogba a run-out," said Ferguson.
"It depends because there are a lot of players who need a game; Nani, Young, Hernandez, Cleverley, Smalling, Jones.
"Those players will all play tomorrow and we hope to put a sprinkling of experience amongst it."
Rooney was the only significant absentee from Wednesday's training session, with Anderson taking part after injury and Michael Owen also doing some light jogging.