Sir Alex Ferguson is hoping Darren Fletcher can make a full recovery from the chronic bowel condition that has ruled him out for the foreseeable future, but has refused to put a timescale on the Manchester United midfielder's return to action.
It was announced earlier this week that the 27-year-old will take an extended break from the game in a bid to recover from a problem that has plagued the Scotland captain for the past year.
Fletcher missed two months towards the end of last season due to the illness, and also sat out of the Red Devils' pre-season tour of North America to continue working on his fitness.
After returning to action in September's Euro 2012 qualifiers, Fletcher went on to make 10 appearances for the reigning Barclays Premier League champions this season, but will now be unavailable for selection.
With the likes of Tom Cleverley and Anderson already sidelined through injury, United's central midfield ranks already look depleted, and Ferguson admits the loss of Fletcher will be a big blow to the team.
But the 69-year-old Scot is adamant that the right decision has been made to give the midfielder the time needed to recover.
"The medical people have made the right decision," he said. "They regarded Darren's health as the more important issue and we as a club agree with that.
"He's not been in training - he's been in hospital for a few days. He'll rest now.
"He's a loss - he's such a great professional and it's not easy to replace that, but we'll think about that. Hopefully he'll make a full recovery.
"It's obviously going to take a bit of time and rest is the most important thing at the moment. I can't put a timescale on it."