Fletcher set to return next season
The Scotland international has not played since November after suffering a serious bout of ulcerative colitis, a problematic bowel condition.
The 27-year-old is remaining positive as he continues his recovery from the problem and has taken over some of the coaching responsibilities that Paul Scholes abandoned when he came out of retirement.
The combative midfield man is now hoping to return stronger than ever before next season and has expressed his thanks to those that have given him support.
"I'm still not ready to come back playing or training yet but I'm listening to the medical people and trying to get myself right," he said.
"The challenge and the focus is to be ready for next season.
"Me and the medical team decided it'd be best if I tried to get myself right and take an extended period out from the game; then come back fully fit and ready to play.
"It's an unpredictable illness and you don't know what lies ahead of you. But I've got to keep staying strong and keep believing. That's an important side of it: positive thinking.
"I've received great support from everyone in Scotland and down in Manchester. I'm hopeful and really positive that I'll be back and back to my best."