Arsenal must have a successful first leg at the Emirates Stadium if they are to have any chance of defeating last year's runner-up Bayern Munich in the Champions League round of 16.
At this stage of the competition last year, Arsenal lost the first leg 4-0 at the San Siro to Serie A club AC Milan, which put the Gunners in a very difficult spot heading back to London for the second leg.
Who will win the first leg?
Arsenal nearly completed a thrilling comeback, but fell just short in the home leg with a 3-0 victory, which resulted in a 4-3 loss on aggregate.
Arsene Wenger must stress the importance of playing well in the first leg to his players, because his team does not this year have a dominant scorer such as Robin van Persie, who can help erase a first-leg deficit.
Going into the Allianz Arena following a victory in the first leg would give the Gunners an incredible amount of confidence.
These clubs met in the 2001 Champions League quarterfinal, and Arsenal did not build a lead for the second leg in Munich. They drew with Munich 2-2 at Highbury before losing 1-0 in Germany. That Munich squad won the competition, and this year's team is just as talented.
There are very few weaknesses on this Munich team. They have an elite goalkeeper in Manuel Neuer, arguably the two best wingers in the world in Arjen Robben and Franck Ribery, as well as a top striker in Mario Gomez. Bayern can also play any style of football and have a ton of experience in this competition.
After losing the Bundesliga title last season to Borussia Dortmund, Munich have built a strong nine-point lead in the table through 17 games this year and are playing some brilliant football.
Munich were 1-1-1 away from the Allianz Arena during the group stage, and scored just three goals while allowing four. They are not the same team when they travel outside of Germany, so it's very important for Arsenal to win at the Emirates in the first leg.
Defeating Bayern at the Allianz Arena is an incredibly tough challenge. The German club was 3-0 at home during the group stage, and in Bundesliga play, Munich are 6-2-1 in front of their supporters.
Arsenal are just 3-4-2 on the road in the Premier League this season, and it's hard to imagine them being able to make a comeback against one of the best teams in Europe if they fail to impress in the first leg.
The Gunners do have a slight chance of beating Munich and reaching the quarterfinals of the Champions League for the first time since the 2009-10 season, but they cannot afford to lose the first leg at the Emirates.