The Scotland international, currently away with the national squad for World Cup qualifiers against Wales and Belgium, has not featured in a Barclays Premier League match since November 2011 after being diagnosed with ulcerative colitis. He has played in the Champions League and Capital One Cup this season, but is still waiting for the call in the league.
"It's what it's all about, getting as many games as possible," Fletcher, who has also played for the under-21s and in behind-closed-doors games to help his fitness, told MUTV.
"I know the manager has got such a big squad now, especially in the midfield area, and there is a lot of competition for places.
"I have to be patient and wait for my chances but, hopefully, one will come around sooner rather than later.
"I think my general fitness is fine, it's just match fitness - the sharpness, reaction times, things in your head and things like that.
"The positional sense, when you're a little bit older, comes back to you fairly quickly."