The Portuguese boss will be looking to get the campaign back on track after stumbling to seventh place, five points behind Manchester City.
Mourinho’s preparations for the trip to Anfield have been disrupted by the international break, but all of his players have returned fit and well.
Speaking ahead of the game, Smalling revealed what Mourinho told his players.
“It’s one of those where the manager has stressed again this week we need to keep our emotions in check because even players who haven’t been at United long know how important this fixture is,” he said.
“It’s about controlling our emotions and keeping all our men on the pitch. It’s a game where I think you need to play to your maximum.
“All week, we’ll be working on tactics and quite often, in the first 15 minutes, the plans can go right out of the window until the game settles down.
“It’s one of those where we must keep a cool head and implement our game plan to exert pressure on them.”
It’s set to be a big fixture for both sides, but it’s almost a must-win game for Man United as the pressure is starting to build on Mourinho and his squad.
After an impressive start to the season, Mourinho’s side have stumbled and will be looking to prove they’re back with a convincing win over Jurgen Klopp’s in-form Liverpool at Anfield.