Bruno Fernandes has promised Manchester United fans that Ole Gunnar Solskjaer's side will secure a place in the last-16 of the Champions League.
United required a point at home to Paris Saint-Germain on Wednesday to book their place in the next round.
Neymar opened the scoring for the visitors before Marcus Rashford's deflected shot beat Keylor Navas. Thomas Tuchel tweaked his system after half-time which resulted in two more goals for the Ligue 1 champions.
RB Leipzig's win against Istanbul Basaksehir means United must avoid defeat against the Bundesliga side on matchday six to reach the knockout stages.
Fernandes has promised United supporters the players will do what is needed to progress.
He wrote on Instagram: "Heads up, we have to fight until the last game and we will do it."
United will be without Fred for the game in Germany after the Brazilian was sent off for two bookable offences at Old Trafford.
Solskjaer believed the second booking was unjust but admitted he should have substituted the midfielder at half-time.
He said: "It's not a foul. Fred played really disciplined in the second-half and when he makes a tackle like this you can't really fault the boy.
"We said at half-time just be sensible and he was, he played well. When the decision the referee made you maybe look back but there was no reason from his performance to take him off. He was lucky to stay on in the first-half but the referee made a mistake there, that's allowed."
