Sanches returns to Bayern training
The 19-year-old, who joined the Bavarian giants from Benfica for 35 million euros ($39.6m) in the close-season, suffered a thigh injury in training a fortnight ago after helping his national side win the Euro 2016 title.
New coach Carlo Ancelotti will make his Bundesliga bow as Bayern kick off their search for a record fifth consecutive title by welcoming Bremen to the Allianz Arena.
Douglas Costa, Arjen Robben and Jerome Boateng are all also struggling with injuries.
But Spanish midfielders Thiago Alcantara and Xabi Alonso are back and fully fit, after being rested for the German Cup first-round 5-0 win over Carl Zeiss Jena last Friday.
Last week, Italian Ancelotti brushed off any concerns about the depth of his squad.
“I’m happy with this team,” he said.
“We do not need new players. The injuries will last maybe two or three weeks, so we can hold up there.”