Fletcher returned to United’s midfielder for the draw with CSKA Moscow on Tuesday. The Scot has been out of action for a month with an ankle injury.
“Sunday is a massive game, games against Chelsea always are,” he said.
“It is not going to make-or-break who wins the league by any means, although it is an important benchmark.
“Maybe psychologically it might have an effect. But Chelsea are a top-class side and we will respect them. It would be good to win.
“We have had a couple of draws down there but we have still not managed to win in the league and we are desperate to do it.
“But we will go there with a game-plan and try to get a result.”
