Hard to see a team that has given up more than 2 goals just once this season being easily carved up by Atletico, Xabi or not. Maybe Pep will trust Kimmich to play in Xabi's place when Boateng comes back now that Kimmich has played well in several important matches. Boateng could replace Xabi's role in distributing the ball to the wings and move more into midfield with the ball, interchanging with Kimmich. With Robben potentially back in the mix as well, Bayern could be a lot better next round. They could still play well with Xabi in the starting lineup, but not as well.
Thats because they play in the Bundesliga where they are far ahead of any team in the league.
They looked very vulnerable against Juve and Benfica.