United have not secured a league win at Stamford Bridge since 2002. However, already four points adrift of the current leaders, United are aware that defeat will place them in a very tricky position.
"I am not looking for it to be a classic, I am just looking for the win," he said. "We need a result. It has been a while since we have had a win there and we know they are in great form in the league."
He added: "It is a different Chelsea side now. It used to be a big strong physical side whereas now you are facing something more like Barcelona, the small intricate players who get in pockets behind you and play killer passes."
Fletcher admits it would represent the biggest game of his comeback if he was selected.
The Scot is realistic, though. With just three starts since he returned to first-team duties following the revelation he was suffering from a chronic bowel condition, Fletcher is delighted just to be in contention.
"If selected, it would be the biggest game of my comeback. But either way, I am back a lot quicker than I expected," he said.
"Maybe I don't have the sharpness in my legs yet but I can react quicker because I have been in situations before.
"My legs are coming back. If you had said I would be in this position back in June and July I wouldn't have believed you.
"I always appreciated how fortunate I was. But after going through something like this, you appreciate it more without a shadow of a doubt."