Mourinho demands intensity against Young Boys
Mourinho's men are two points off Group H leaders Juventus and two ahead of third-placed Valencia following the 2-1 come-from-behind win in Turin earlier this month.
Subsequent Premier League results have been less impressive - a 3-1 defeat in the Manchester derby followed after the international break by Saturday's uninspiring 0-0 draw at home to Crystal Palace.
United remain well placed to advance in Europe but Mourinho, who admitted his midfield lacks "aggression", wants his side to shed their lethargy on Tuesday.
"It's not a crucial match because if we don't win tomorrow we still don't depend on other results. We will still just depend on ourselves," Mourinho said.
"But I want to play from the first minute like it's the last chance we have to qualify. I want to play this game like a knockout game, like we have to win.
"The team I'm going to play, I [want to see] happiness to cope with the little pressure I'm going to try to add to the players.
"That's not real pressure because the reality is we still have one match to play. Let's forget about Valencia and Juventus. Let's play this game like a game we have to win.
"We had good periods of football [on Saturday] and then periods of low intensity," says Jose. "I want the team to start strong. I want them to have a go immediately so it was a bit frustrating." #MUFC
— Manchester United (@ManUtd) November 26, 2018
"I don't want the team to be waiting, not to be reactive but proactive. You or the fans probably think Jose told [the players] to start slow and nice and easy, or to wait to react.
"It's the exact opposite. It's frustrating."
United are at risk of going winless in four straight European matches at Old Trafford for the first time in their history, but the Red Devils boss denied his players would rather play away from their own ground.
"I think it would be a lack of respect to the stadium and the fans to say we prefer playing away," the Portuguese said.
"If you ask me if I prefer to play at home against Young Boys or to go away to Bern, I prefer always to play at home.
"If you feel pressure where people come to support, stay and watch on TV. I never feel pressure at home."