Manchester United midfielder Darren Fletcher has been forced to take an "extended break from football" due to concerns about his health, with the club revealing he has been suffering from chronic bowel problems.
Fletcher, 27, missed two months of last season with a then-unspecified virus - which United have now revealed was ulcerative colitis - and when he returned to first-team action had lost a significant amount of weight.
The Scotland captain was also absent for part of pre-season training as he continued his recovery and has started just seven games this season.
With the condition taking a major physical toll on him and his long-term health a priority, Fletcher has been advised to stop training and playing for a sustained period.
A statement from United read: "On behalf of Darren Fletcher, Manchester United wishes to announce that he is taking an extended break from football for health reasons.
"Over the past year he has had several absence periods which we have attributed to a viral illness in order to respect his right to medical confidentiality. Darren has, in fact, been suffering from ulcerative colitis (a chronic inflammatory bowel condition) for some time preceding this.
"Whilst he was able to maintain remission of symptoms for a considerable period this has proved more difficult recently and Darren's continued desire to play and his loyalty to both his club and country has probably compromised the chances of optimising his own health and fitness.
"He has therefore accepted medical advice to take an extended break from the demands of training and playing in order to afford the best chance possible of achieving full remission once again.
"We request that his privacy is respected and hope that the removal of the additional stress associated with speculation regarding his health will also aid his recovery."
Team-mate Tom Cleverley hopes United can show they have sufficient quality in their ranks to cover for the loss of Fletcher.
"I'm afraid it's bad news for him and bad news for the team,'' Cleverly told Sky Sports. "He's a massive player for us and it's a shame because we're having a bit of a problem in centre midfield but we've got Giggsy (Ryan Giggs), Ji (Park Ji-sung), Carras (Michael Carrick), Phil Jones doing a job, and Darron Gibson still in the squad, so that's what squads are for.
"He's a fantastic pro, Fletch. He's someone I've always looked up to.''
Scotland boss Craig Levein was dismayed to hear the news about Fletcher's illness, saying: "I am obviously absolutely devastated for Darren because I know how hard he has worked to get back to playing regularly for his club and country.
"He is one of the most inspirational players I have had the pleasure of working with and on behalf of his Scotland team-mates and my backroom staff I sincerely hope this time off, allied to the support of his family, will enable him to make a full recovery.
"Darren has shown tremendous dedication and fortitude, demonstrated by his ability to overcome this illness and perform at the highest level for Manchester United and Scotland. I spoke with Sir Alex Ferguson and Darren this week and the most important thing at this stage is for the player to be given time to rest and recuperate.
"Nobody is more committed to his country's cause than our captain. He is a central part of our plans for the World Cup 2014 qualifiers but at this stage his health is paramount and I would like to reiterate the best wishes of everyone at involved with the national team and the Scottish FA.''