Hansi Flick's side looks increasingly fatigued, but in a game of this magnitude he can't afford to rest his stars.

The UEFA Champions League returns for one final round of matches before the new year, with much at stake for several European heavy-hitters. Wednesday's action features Barcelona's trip to Borussia Dortmund and Manchester City taking on Juventus.

FC Barcelona head coach Hansi Flick will go all out against Borussia Dortmund in the Champions League on Wednesday.