Bayern Munich's Dutch star Arjen Robben and Germany midfielder Toni Kroos will both miss Wednesday's Champions League clash at Premier League leaders Manchester City with flu.
Robben has only recently returned after groin surgery in October and Bayern's director of sport, Christian Nerlinger, said he cannot play, despite the Dutchman having scored twice in Saturday's 4-1 win over Werder Bremen.
The loss of Kroos is almost a bigger concern in the defensive midfield zone, with Bastian Schweinsteiger still recovering from a broken collarbone sustained on November 3.
Forward Thomas Mueller and Belgian defender Daniel Van Buyten are also showing flu-like symptoms, but it is hoped they will play.
Coach Jupp Heynckes still has the Ukraine's Anatoliy Timoschuk, Austrian David Alaba and Brazilian Luiz Gustavo to call upon in the centre of the pitch.
"We will do everything to bring the points home. We are at the top of the group and we want to win every game," said Bayern captain Philipp Lahm.
With 13 points, Bayern are guaranteed to finish first in Group A, while City, third with seven points, must win at their Etihad Stadium and hope bottom side Villarreal secure at least a draw at home to Napoli.
Roberto Mancini's team are five points clear in the Premier League after 12 wins from 14 matches, but have struggled in their first Champions League campaign and appear set to drop into the Europa League.