Bayern Munich need to fix key problem before blockbuster clash against Arsenal

Bayern Munich returns after the international break with a banging performance, putting six goals past Freiburg and showing the world their attacking prowess.

Yet the performance still has a sense of incompleteness with Manuel Neuer conceding two goals in less than 15 minutes of action. Both of which came from corners.

Trouble with dead balls

Bayern has been the most fearsome attack all across Europe. Die Roten's open-play defense has also improved tremendously with the magnificent link-up of Jonathan Tah and Dayot Upamecano.

However, their set-piece defense still stands out as a glaring weakness: the last four goals Bayern Munich conceded were all from set pieces.

The first Freiburg goal this past weekend came from a near-post delivery that was flicked onto the middle of the box for a tap-in. The second one was aimed towards the far post for Johan Manzambi to head it in from close range.

Look further back into the Union Berlin game, and both goals were rooted in individual mistakes from Bayern players defending the set piece, with Neuer bobbling the ball into the net and Kane's terrible clearance.

In the DFB-Pokal tie against Cologne, Bayern also let in a goal from a corner, as well as plenty of other chances that could have led to more goals had it not been for Jonas Urbig's excellent reflexes.

Getting "zoned" out

Bayern set-piece coach Aaron Danks loves to operate the defense in a zonal marking system, meaning no player is responsible for any direct matchup and rather focuses on defending the aerial space above their head.

Another key point is that Bayern often chooses to flood the box with bodies, leaving Luis Diaz as the only counter-attacking threat at the edge of the penalty area.

In theory, more men equals more defense and stability, and zone defense means more area well guarded. However, this is not the case in modern set-piece football.

Teams have increasingly used more movements pre-crosses to disguise their positioning. At the moment the crosses are whipped in, the opposition can attack the gaps between the Bayern players, causing a lot of confusion by their surprising runs.

Another way to attack Bayern's vulnerable setup is exactly how Freiburg executed in the first goal: a near-post low cross attracting a lot of movement, which leaves acres of space at the edge of the box.

Furthermore, Bayern Munich also lacks the personnel to win aerial battles. Jonathan Tah is decent, but Upamecano has never excelled in the air compared to his ground-duelling ability. This poor track record will most likely not end well come Wednesday night at the Emirates.

The kryptonite

While Bayern is struggling to defend corners and free kicks, Arsenal has made a living out of set-pieces. With set-piece wizard Nicolas Jover at the helm, they have scored 12 goals this season from dead balls, more than any team in the Premier League.

The Gunners use a lot of movement to block and disguise their runs, which can become a huge problem for Bayern's defense.

They also have towering players like Calafiori, Saliba, Merino and Timber who can outjump anyone. It is quite a blessing for Bayern that Arsenal's number one set-piece threat, Gabriel, is out of the equation due to injury.

Also, Bayern fans cannot fully rely on the offense to make amends for all the defensive failures, as Arsenal is also one of the best defensive units in football right now. Vincent Kompany and Aaron Danks will need to fix this issue quickly before the Champions League anthem rolls around in a few days.