Sascha Schuermann/Associated Press
Pep Guardiola has revised last season's tactics by creating a three-man defense, but that adjustment hasn't yet proven to be a wise move. The tactic was exposed against the MLS All-Stars in Bayern's final preseason test, and again looked very shaky against Dortmund.
Javi Martinez (who was substituted off after half an hour and taken into the tunnel on a stretcher) was often either too high up the pitch or too deep, leaving space for Dortmund to attack either behind the back line or between the defense and central midfielders.
He may be a great holding midfielder, but the Spain international still lacks the positional understanding that top center-backs usually only learn in their mid-20s after several years of regular play in that position.
In any case, it may be a long time before Martinez next plays. Sky reported shortly after his injury that the ex-Bilbao man may have torn his anterior cruciate ligament.
To Martinez's left, David Alaba also was not always convincing. Although the Austrian's pace is a huge advantage to a back line that has often been criticized for being too slow, he lacks the frame and strength to play as a center-back. His challenge before Henrikh Mkhitaryan's opener was rather weak.
In fairness, the Bayern defense had little screening from Gianluca Gaudino, who at 17 years of age still is far from physical maturity and lacks the strength and explosiveness required to play in central midfield at a high level. That will come in time, but it's a matter of waiting for biological factors to kick in.