The two managers have clashed in the past - particularly dating back to their spells in charge of Chelsea and Liverpool respectively - and will renew their rivalry again this weekend when Benitez takes his winless Magpies to Old Trafford.
The Red Devils are in poor form themselves, though, and Mourinho is expecting another "difficult match" given Benitez's tactical acumen.
"We know our opponent also needs points," Mourinho told reporters at his pre-match press conference.
"They have a very, very, very good coach, a team that is always well organised against teams of the first part of the table. The manager is very bright at analysing opponent's qualities and trying to stop them.
"The results they had against the top teams didn't get them points yet this season but they gave them very, very close results and difficult matches for the opposition, so we expect a difficult match."
Newcastle have beaten Manchester United just once at Old Trafford since 1972.