With old injuries and new injuries, Bayern Munich's squad is in a very delicate state. This unfortunate middle state has left Bayern with 13 field players and two goalkeepers available for selection, able to fill the team sheet just enough for three substitutes.
The situation is almost as bad as last season when Bayern could not field a potent side against Barcelona. However, Pep Guardiola can still get creative with the players he does have, especially against a weaker side like Werder Bremen. He will have to make tactical tweaks not only because he is able to, but because he has to with such a thin squad.
1. Douglas Costa as a wingback
Douglas would not actually play as a true wingback, for his responsibilities will still be high up the field. A potential wingback role would only come about if Guardiola elected to play with three at the back, a definite possibility considering Bremen's usual setup. The only other example of this in actual competition is Bayern's 7-1 victory against AS Roma in the Champions League last season, where Arjen Robben "played" as a deeper midfielder in a three-back system. Douglas's defensive work rate is high enough for him to handle Theodor Gebre-Selassie's advances forward, and could still smoke the Bremen right back with his take-ons.
Why it would not work: Though Douglas occasionally runs around like a midfield destroyer, his ability to close down the ball is not very good. Besides, Guardiola would only want a three-man defense if he wanted to stuff another midfielder in the center of the park. Bremen's tight setup leaves the flanks pretty wide open, so leaving Douglas out there by himself would not be taking advantage of the afforded space.
2. Joshua Kimmich as a playmaking midfielder
For most of his Bayern career, Kimmich has sat pretty deep in Bayern's setup, usually playing the exact No. 6 role Xabi Alonso plays. He was much more versatile than that when he played for RB Leipzig last season, and he reminded spectators of that over the weekend with the U21s. He can more than hold his own in a higher midfield role, and with Arturo Vidal on the shelf, he may get a shot to prove that against Werder Bremen.
Why it would not work: If Alonso is unable to go from the start, or if Guardiola wants to spare his 33-year-old Spaniard for the Champions League, either Kimmich or Philipp Lahm will have to sit deep in midfield. It also does not help Kimmich returned late from his time with the U21s after facing the Faroe Islands on Tuesday, so a higher attacking role may be too taxing for the youngster.
3. Juan Bernat as an attacking winger
Playing Bernat as a left-sided midfielder is not the strangest thing in the world considering he basically played there at times last season. In fact, his interchange with David Alaba a year ago was pretty effective, and was an acceptable solution when Franck Ribery was injured last season. Guardiola has an opportunity to be very creative with his flank players, and Bernat adds to that creativity.
Why it would not work: Bernat has missed the last few weeks with a groin issue, so staring from the outset may not be an option quite yet. His inclusion may make Bayern rather static in attack too, limiting the different ways they can go at Bremen's overaggressive defense.
4. Javi Martinez at the tip of a defensive diamond
Martínez in midfield? WHAT!?! Throw back... This tactical nuance would only come about if Alonso was held out of the side and Guardiola wanted Lahm's presence on the flank. That said, Guardiola may want to win the ball higher up the field, and with Arturo Vidal out of the side, Martínez is the best midfield destroyer Bayern has. Bremen's midfield is not the best at winning the ball in the air either, an attribute Martínez can surely exploit.
Why it would not work: To be candid, this is the least-likely tactical tweak that will happen. Martínez himself admitted he is not fully fit, so a taxing midfield role may not suit him either. Guardiola is more likely to play with a simple back four and have Martínez and Jerome Boateng come forward if the No. 6 options are limited.