"We have two very important targets at the end of our season," Sarri told reporters. "The first is the top four and the second is to get to the final of the Europa League.
"For the first target, this match is more than important for us and for our opponents. So we will try to win, of course, but we need not to lose. It's a very difficult match for both I think."
However, Chelsea are yet to win a single point away at a 'top six' club this season. They have lost four games, conceding 13 goals and scoring only one, and face a United side hurting from a 2-0 midweek humbling at the hands of Manchester City.
"In the second half of the season we face the big teams away, only Tottenham at home," Sarri added. "It's not easy. We have to play against opponents with a very high level of motivation after the Manchester derby. But we have to try."
Sarri also said Chelsea forward Eden Hazard deserved to be named in the Professional Footballers' Association's (PFA) Team of the Year that was dominated by players from title contenders Manchester City and Liverpool.
No player has been involved in more goals than Hazard in the league this season (16 goals and 13 assists) and Sarri was of the opinion that Chelsea's position in the table was the reason behind the snub.
"I think that Eden deserved to be in the top of 11 of the Premier League," Sarri said. "But I think also at the moment the table is clear. There is City, there is Liverpool, and then the other teams. So I think the vote was influenced by the table."
The Italian boss confirmed Chelsea winger Callum Hudson-Odoi would be sidelined for three months with a ruptured Achilles he sustained in the 2-2 draw with Burnley. Defender Antonio Rudiger could return while midfielder N'Golo Kante remains a doubt.
"Rudiger is OK at the moment. We are trying to recover Kante but I am not sure at the moment," Sarri said.
(Reporting by Rohith Nair in Bengaluru; Editing by Christian Radnedge)
