Kimmich, 31, missed Bayern's final training session, with assistant coach Aaron Danks initially citing personal reasons for his absence on Tuesday.
The club confirmed on Wednesday that Kimmich would not be part of the squad as he deals with the family bereavement.
"On behalf of the family, we ask that his privacy and grief be respected, and that further inquiries and reporting be refrained from," Bayern said in a statement on X.
Kimmich's absence is another setback for Bayern, who are also without suspended winger Michael Olise for the group-stage encounter at the Allianz Arena.
The German side will nevertheless take confidence from Saturday's 6-1 Bundesliga win over RB Leipzig as they look to build on last week's entertaining 3-3 draw away to Viking in Europe.