That’s according to former Arsenal and England star Martin Keown, who says the Red Devils need to use the fixture to close the gap on Pep Guardiola’s Premier League leaders.
United are currently second in the table having collected 32 points from their opening 14 games of the season.
They’re already a distant eight points adrift of rivals City though and face Arsenal before they welcome the Blues to the Etihad.
Keown has now outlined how Mourinho needs to approach United’s showdown with City on Sunday December 10.
“The last two matches have been tricky for City,” Keown told the Daily Mail, when asked how Guardiola’s side can be beaten.
“At the weekend, Huddersfield got everyone behind the ball and City struggled to find a way through. Is that how you stop them?
“When City play against the big boys, they know their opponents will want to play against them. Where they have found it tricky is when teams have shut up shop.
“I do feel teams could ask more questions of City’s central defenders. Vincent Kompany has returned from injury but has not been tested much in these last two games.
“City leave a lot of space behind their full backs and their opponents need to exploit…