Bayern's next game is as easy as it gets: Holsten Kiel. HK got promoted to the Bundesliga this season and have so far lost the first 2 games, making them a massive underdog against Bayern and I don't think home advantage would be much of a help.
The problem is, Beyern is playing an opening round against Dinamo Zagreb on Tue, the week after, so Kompany might be tempted to let some key players rest on Sat, to make sure they're 100% on Tue. But at this stage, Kompany and the club are almost definitely more focussed on winning back the Bundesliga than on the Champion's League, so I imagine they will approach Saturday's game with full seriousness and maybe if all goes to plan and if they work out more than 1 goal advantage, he'll let some bench players in earlier.
But if Bayern is also committed of getting through the group stage of the UCL, they really need to win with Zagreb, as next games will be much harder (Aston Villa, Barcelona, Benfica, PSG).