Bayern Munich's Ruckrunde has thus far been defined by two themes: the loss of every centerback on the roster to varying forms of injury, both short and long term, and the rise of Joshua Kimmich who has taken to a role in Bayern Munich's backline like a fish to water.
Enter stage left, Xabi Alonso. The Spanish centerback has long been one of Guardiola's favored tools, much to some people's joy and much to other people's (points at self) irritation. On the offensive side of the ball, Xabi Alonso has been one of the key cogs for Bayern. His distribution and vision from deep is this team's metronome. On the defensive side, his inability to move has been a source of problems and while Alonso to his credit has really stepped up the defensive side of his game this year, it's still a weakness.
And it's likely the magnitude of that exact weakness that has prevented Alonso from stepping into the Bayern Munich backline despite the fact that he's one of the few remaining players who is a) a good tackler and b) an aerial threat. Instead it has been Kimmich who has shouldered that role despite a lack of aerial ability and almost zero tackling ability. Given that the 20-year-old has become this team's distributive hub from deep, it's likely we're seeing the transition of this Bayern Munich team away from the Alonso.
While Joshua Kimmich ostensibly plays as a "centerback" in positioning, his play type eschews almost every part of the game traditional centerbacks use. So while it may be appropriate to call him a centerback it would be inappropriate to evaluate his performance based on the same skill sets that tend to define that position. It's yet another in a long sequence of roles Pep Guardiola has had to twist to fit into a tactical schema that either fits his players best, or to address the absence of key cogs in his team.
Alonso meanwhile has not featured in any meaningful way for Bayern Munich since their win over Bayer Leverkusen (sadly, we don't have passing maps for Bayern's win over Bochum where they both played). Looking at Kimmich's passing maps from the time leading up to this match and afterwards, there is a clear trend as Kimmich has moved away from the more centerback oriented tight passing approach towards a more expansive, distributive passing selection. That rise of actual playmaking from deep has allowed Arturo Vidal more space in the middle as the lone holding midfielder and shouldn't be discounted when we talk about the resurgence of his play in recent weeks.
Coupled all of this with the fact that in the most critical game this season to date, it was Joshua Kimmich who Pep Guardiola chose to his team through and Xabi Alonso. And as Pep Guadiola said, "He was perfect. His performance was perfect. He also won the long balls against Mandzukic." That perfection likely isn't the defensive component of his game (hello, Juventus) but the fact that Kimmich is this team's metronome at the back now. He's doing the unheralded work that's allowing Arturo Vidal to shine in the middle.
Only time will tell if Pep Guardiola sticks with Kimmich over Alonso once Bayern's centerback corps return to full health. A fully healthy Bayern doesn't need Kimmich to play this kind of role, but for now it's working well and if Kimmich can boost the defensive side of his game, there's no reason that Bayern couldn't ride this weird setup all the way to three more trophies.