Round of 16 2nd LegTodayBayern     vs     Arsenal        21:00 SS3Malaga     vs     Porto        21:00 SS3MUNICH – Arsenal must stage one of the most unlikely Champions League comebacks if they are to advance at the expense of hosts Bayern Munich in their round of 16 second leg clash on Wednesday.Bayern silenced the Gunners 3-1 in London last month to put themselves in the driving seat for a spot in the quarterfinals for the third time in the last four seasons.Only twice in the Champions League has a team lost the home leg of a knockout round match and survived by winning the away leg. Ajax Amsterdam did it in 1995-96 against Panathinaikos and Inter Milan did it in the last 16 in 2010-11 – coincidentally against Bayern.The Germans won 1-0 in Milan in the first leg, before losing 3-2 at home and going out on the away goals rule.Arsenal though have two goals to make up and must overcome the psychological disadvantage of having been completely outplayed by Bayern in north London – something coach Arsene Wenger was at pains to point out before the squad left for Germany."We’re chasing the game in a very difficult environment against a team that has no doubts at all,” he said."Our mentality is to go there, not resigned, but ambitious and provoke things, not go there and think ‘we will not qualify anyway’. Arsenal are likely to be without defender Bacary Sagna who is nursing a long-term leg injury though Germans Per Mertesacker and former Bayern player Lukas Podolski would love nothing more than a victory back in their homeland.The Bavarians, on the other hand, are enjoying a sparkling season and despite three key absences, should advance to the quarterfinals and a step closer to a Wembley final."At the moment everything seems to work perfectly,” said Bayern keeper Manuel Neuer after his team twice came from a goal down to beat Fortuna Dusseldorf 3-2 on Saturday and go 20 points clear at the top of the Bundesliga.Bayern, who have reached the final twice in the last three seasons, will be without injured winger Franck Ribery, enjoying his best season yet at Bayern. He will join suspended defender Jerome Boateng and holding midfielder Bastian Schweinsteiger on the sidelines.