The Red Devils slumped to a 2-1 loss at Stamford Bridge, despite taking the lead against the reigning champions, and the Scot admitted United were frustrated to drop three points.
“You could not have a better game to get the frustrations of Tuesday night out of our systems," he said.
"It is a weird thing to say about a match between Liverpool and Manchester United but if anything it has become even bigger because of what happened at Stamford Bridge.
"There is a lot of disappointment because we never seem to get the rub of the green down there.
"We have to bounce back quickly and get all our focus and energy on Liverpool."
The Scotland captain admitted the fierce rivalry between the two clubs meant there would be an intense atmosphere at Anfield, particularly with United aiming for a 19th league title, which would be one more than Liverpool.
"It is part of football rivalry that there might be more incentive from stopping us achieving stuff than what they can do themselves," he added.
"Liverpool are a proud club with a great tradition. They certainly won't want to relinquish the record to us.
"However, we are going there to get our title challenge back on track so it is not as though we are lacking an incentive to win."
Fletcher also feels a win for the Red Devils, which they haven’t managed on their last two visits to Anfield, would give their title hopes a big boost.
“You want to be top at this stage of the season," he explained.
"You want to have it in your hands. You don't want to be relying on anyone else.
"That is what getting back to winning ways on Sunday would do.
"It is still in our control and we want to keep it that way through until the end of the season."