The Dutchman had been out for two weeks with a groin injury and while Bayern kept winning in Germany and Europe, they looked far less sharp doing so.
A narrow 3-2 win over Hertha Berlin was followed by another nervous 2-1 victory at Hoffenheim last week that saw them equal Hamburg SV's 36-game unbeaten run but their performance was far from their best.
A struggling 1-0 win over Viktoria Plzen, which booked their spot in the knockout stage of the Champions League with two game to spare and their best ever group performance after four games, sounded alarm bells.
For any other team this would still be a perfect run but Bayern fear they could become complacent.
"We need to quickly make sure we do not oversleep in the opening stages of games as we have been doing in the last few weeks," Bayern captain Philipp Lahm said.
Robben's return to spice up their game with his darting runs could not have been timed better with the winger back in training on Wednesday and expected to feature in coach Pep Guardiola's squad, the club said.
For fellow Bavarian club Augsburg, in 13th place, the question is not who will score goals but rather who will be in goal with coach Markus Weinzierl deploying all three keepers so far this season.
Swiss Marwin Hitz surprisingly won the nod in their 2-1 win over Mainz 05 last week and paid back the trust with a good game.
"Sometimes you make difficult decisions as a coach but you have to and sometimes you are rewarded," Weinzierl said after Witz's solid performance.
This kind of risk-taking will be necessary if they are to get anything out of a game against unbeaten Bayern and move further away from the relegation zone.
Second-placed Borussia Dortmund will look to bounce back from a 1-0 Champions League defeat to Arsenal when they travel to improving VfL Wolfsburg, who have won their last three games to climb up to fifth.
Dortmund are on 28 points from 11 games, one behind Bayern.
Bayer Leverkusen, in third spot on 25, entertain Hamburg, in 14th place after a 2-0 defeat to Borussia Moenchengladbach last week.