Manchester City manager Pep Guardiola dismissed suggestions Jose Mourinho and United would gift Arsenal a win on Sunday.
Mourinho has said he will rest stars for the trip to the Emirates Stadium due to a busy run of fixtures and with his side outsiders to claim a top-four finish.
Manchester United are fifth in the table and just a point and place behind City, who host Crystal Palace on Saturday.
But Guardiola believes Mourinho would never give up on an encounter, expecting United to target victory against sixth-placed Arsenal.
"I am pretty sure United are going to go to London to win the game," he said.
"What I know a little bit from the times I faced my colleague, Jose Mourinho, he is never going to drop one game."
With Chelsea clear at the top and Tottenham well-placed in second, Liverpool (69 points, 35 games), City (66, 34), United (65, 34) and Arsenal (60, 33) are looking to finish behind them.
However, United are on track to reach the Europa League final, having beaten Celta Vigo 1-0 away from home in the first leg of their last-four tie.