Mourinho fell under heavy criticism following United's performance away at Anfield earlier in the season, a game which ended in a goalless draw.
The Red Devils managed only one shot on target in that game, which Bruce insists cannot be repeated in the return fixture at Old Trafford.
"They can't park the bus," Bruce told talkSPORT. "The supporters will demand that they go and have a go at them, that is for sure.
"You are going to have to defend well because Liverpool's undoubted strength is the front three and the pace of the front three.
"They are fantastic to see at the moment Liverpool but [United] will have a game plan that they can't be caught on the counter-attack so be careful of it."
A loss to Liverpool would see Mourinho's men drop to third in the table, with Liverpool taking their place in second behind league leaders Manchester City.