Arsenal defender Per Mertesacker has claimed that Bayern Munich present an even greater challenge than in previous seasons.
The Gunners host Bayern on Tuesday night with their Champions League hopes hanging by a thread after defeats to Dinamo Zagreb and Olympiacos in their opening two Group F games.
Bayern ended Arsenal's bid at the last-16 stage in 2014, and Mertesacker believes that Pep Guardiola's side are better than ever ahead of the meeting between the two sides in North London.
"Due to the two defeats, we are facing one of the biggest challenges that a club can face," the German defender told Kicker.
"It is hoped that you can get closer over the years, but the problem is that Bayern are constantly evolving, conjuring up new players like rabbits out of a hat, which again make the difference.
"That makes it even more difficult to beat them at the moment."
Bayern warmed up for the trip to the Emirates Stadium by beating Werder Bremen 1-0 to maintain their 100% record in the Bundesliga this season.
