If Arsenal can overturn Bayern Munich’s 3-1 first-leg lead on Wednesday it would probably be one of the greatest-ever European comebacks

Mission impossible probably doesn’t quite do justice to the task that will face Arsenal in the Allianz Arena on Wednesday night.

Such was the despondency around the Emirates following the 3-1 first-leg defeat to Bayern Munich, Arsenal have been almost entirely written off in this tie. And with good reason.

Bayern are a formidable force in their own stadium, even if it was the scene of their heartbreak on penalties to Chelsea in last season’s final.

They have lost just once in the Allianz Arena this season, when Bayer Leverkusen won 2-1 back in October, one of only two defeats for Jupp Heynckes’ side in 35 competitive matches this season.

Saturday’s 3-2 win over Fortuna Dusseldorf extended Bayern’s lead at the top of the Bundesliga table to 20 points, and was also their 11th successive win, during which time they have scored 29 goals and conceded just four.

Having missed out on silverware last season by losing both their domestic and European finals, and coming second in the league to Borussia Dortmund, Bayern are hell-bent on making sure lightning doesn’t strike twice. They are in the German Cup semi-finals too after defeating Dortmund in the quarter-final last month. This season they want that treble.

Dortmund, coincidentally, were the last side to win by more than one goal at Bayern, having triumphed 3-1 in February 2011, over two years ago.

In the face of such an onslaught of dominance, Arsenal must reverse their own run of away form in the knockout stages of the Champions League that is, unfortunately, lamentable.

The Gunners have not won an away knockout stage game since defeating AC Milan 2-0 at the San Siro at this stage five years ago.

Since then Arsene Wenger’s side have lost seven out of eight away games in the knockout stages, the only exception being a 1-1 draw against Villarreal in the 2009 quarter-final.

So is there any hope at all of an astonishing turnaround next week? What is needed is a victory by a three-goal margin, matching Bayern’s 3-1 win to take the tie to extra time, or eclipsing it with a 4-2 or 5-3 success or some other outlandish scoreline.

Arsenal supporters will surely travel more in hope than expectation, and skipper Thomas Vermaelen admitted that it is a huge task to defeat the Bundesliga champions-elect on their own turf by such a margin.

“Of course it’s not ideal, they are at home, it [the first leg] was not a good result. But we always have to play, you never know in football,” said Vermaelen.

“But Bayern are a good team, they are very disciplined and they work hard as a team. They are a strong team physically, they know their jobs, they know what they have to do and they did it perfectly in the first leg.”

Are there any positives for Arsenal to cling to? Perhaps only one. Bastian Schweinsteiger, Bayern’s captain and talisman, is suspended after his yellow card at the Emirates, and warned his team-mates not to think they are already through.

“We mustn’t underestimate Arsenal, they have some very good players, and we’ll have to give it 100 per cent in the return,” he said. “Arsenal aren’t just dropping by as tourists. The first leg was a good result, but it’s not over yet.”

Schweinsteiger will doubtless reiterate that to his team-mates next week, but the evidence from the first leg was fairly damning.

The ability of Toni Kroos and Thomas Muller stood out in the first leg, and the proven quality of Philipp Lahm, Franck Ribery, Javi Martinez and Arjen Robben, who started on the bench at the Emirates, is there for all to see.

If Arsenal turn this tie around, it would probably go down as one of the greatest European comebacks of all time, given that they must do it away from home, and against such formidable, in-form opponents. You get the feeling the rest of Europe is not holding its breath in anticipation.