Bayern Munich coach Jupp Heynckes maintains his side cannot switch off against Arsenal - even though they already have one foot in the quarter-finals of the Champions League.
The runaway Bundesliga leaders could be forgiven for thinking the hard work had been done after delivering a European masterclass with a 3-1 win in London a fortnight ago.
However, Heynckes warned the Germans - who before last season's final defeat to Chelsea had lost just once at home in Europe to English opposition, and that back in the 1993 UEFA Cup against Norwich - cannot afford to be complacent.
``Last year Arsenal lost 4-0 (away to AC Milan), then in the second leg they won 3-0 - they could have won 4-0, they had the chances, so it shows they are a strong team and capable of making up the gap if they have to,'' Heynckes told a press conference.
``I respect Arsene Wenger very much. He is a top manager and Arsenal are a fighting team.
``They will do everything to get a result here, so we must be on our guard.''
Bayern forward Franck Ribery will miss the second leg at the Allianz Arena, while midfielder Bastian Schweinsteiger and defender Jerome Boateng are both suspended.
Former Chelsea winger Arjen Robben, meanwhile, was not involved at the weekend against Dusseldorf because of a calf problem.
Bayern, though, have the likes of Brazilian Luiz Gustavo and Switzerland midfielder Xherdan Shaqiri ready to come in.
Arsenal boss Arsene Wenger has challenged his players to produce a performance which will define their careers and knock Bayern out against the odds.
Despite his side having travelled to Bavaria without injured England midfielder Jack Wilshere, set for around three weeks out because of an ankle problem, and first-choice goalkeeper Wojciech Szczesny rested, Wenger insists now is the perfect moment for his team to return all his belief with what would go down as one of the greatest European comebacks.
``I am convinced that if this team can find a big game, with a big win, you will see a completely different animal. This season we have fought to find that in the big games and we have another opportunity tomorrow night (Wednesday) and I hope the team takes this chance,'' Wenger said at the Allianz Arena.
``I have a great respect for this team and its attitude and they have not been rewarded yet. It is important for the end to our season that we do it.''
Despite everything seemingly stacked against them, Wenger insists it is not a case of Mission: Impossible.
He said: ``It is a difficult task, we know that, but we think it is not impossible.
``The only way to make it possible is to have a real go and play at our best, that is what we will do.
``I am confident we will be completely focused and up for it, and give it our best shot.
``Football is football - everything is possible.``