Juan Bernat or David Alaba? The leftback conundrum for Pep Guardiola

In recent weeks the Bayern Munich leftback position has come under increasing scrutiny from Bayern Munich fans. This season it has been Juan Bernat who has had the position on lock starting every game until Bayern Munich's 4-1 win over FC Köln. That match saw David Alaba start on the left, as the team put together an emphatic win against a deep lying defensive opponent. It was also one of the first games where Franck Ribery and Mario Götze really shown through with their technical interplay and partnership with David Alaba. Juxtaposed to last weekends performance against Hannover where the interplay between Bernat and Götze/Ribery was rather stiff.

I don't think anyone is saying Juan Bernat isn't a tremendously talented and effective leftback, but going into Champions League season and being reminded of the strength and viability of the partnership between Alaba and Ribery is going to raise questions about whether Bayern Munich should be playing with Alaba at leftback instead of Bernat. To that end, the question arises of are the performances different? Is Juan Bernat actually better suited to this system and should he be the one starting?

In this analysis we're comparing Juan Bernat to two different versions of David Alaba. The first being 2013/2014 David Alaba who played leftback the entire season and provides a good positional line and the David Alaba of this season. The second is this season's version which with Alaba adopting a central playmaking role isn't as good of a direct comparison because positional opportunity makes a big difference with regards to passing and defensive metrics.

On the ball, there is very little difference between Alaba and Bernat. As we can see from Alaba's performance last season, the two are involved in play to nearly the same extent. While Alaba has taken a huge leap forward in touches per 90 this season, that can easily be attributed to his more centralized role as a member of the 3-man backline or his shifts in defensive midfield. Across the board their pass completion rates are all extremely similar and nothing is indicative of any real difference between the two.

On the offensive side of the ball, Alaba and Bernat shoot at the same rate yet it is in the creative department that Alaba is outstripping his counterpart, registering nearly double the chances created. We see the same nearly double increase in Alaba's metrics from last season too meaning this isn't due to a positional adjustment.That's an indicator that belies a better connection with his offensive teammates and the ability to read their runs and put them in positions to make plays happen.

In the duels department, both players line up almost identically with similar Duel% and with Bernat having the slight disadvantage in the Aerial Duels department, mostly because he's three inches shorter then the 5'11" Austrian.

On the defensive side of the equation, Juan Bernat has the advantage in tackles per 90, but across the rest of the spectrum they grade out nearly identical with regards to interceptions, recoveries, and clearances. Which is ultimately the common refrain when comparing the two players. Other then a difference in tackles per 90 and a chances created advantage, these are two very similar players. Choosing one or the other isn't going to have a dramatic difference on the overall Bayern Munich performance.

Yet as I alluded to above with Bernat in the lineup this last weekend against Hannover 96, the left sided partnership with Götze was a struggle while Ribery's addition early in the second half didn't do much to alleviate that issue. While Bayern still won comfortably it's a worrying side that this team can show a noticeable difference in generating offense on one wing and not seemingly be fully integrated. I don't think anyone will begrudge Juan Bernat some time in that regard as what Pep Guardiola asks his players to do is very complex, he's only been a Bayern Munich player since August, and Alaba and Ribery have spent the better part of 4 years cultivating an effective understanding.

The real question though is who takes the reigns from here on out at leftback? Philipp Lahm and Thiago Alcantara are both back in team training and will likely push David Alaba away from the midfield roles when they return, while Alaba's time in central defense appears limited with the full return of Holger Badstuber to the fold. I think it's easy to say David Alaba will play every minute he is able to considering he's consistently been one of Bayern Munich's best outfield player this season, perhaps only eclipsed by Arjen Robben. That may come at the expense of Juan Bernat's playing time but coming down the stretch in the Champions League -- and in an increasingly tough DFB Pokal -- having the partnership of Alaba and Ribery firing on all cylinders may be more beneficial to Bayern Munich.