Jupp Heynckes texted his congratulations to Bayern Munich after missing his side's Bundesliga win over Schalke with the flu, assistant coach Peter Hermann said.
Heynckes was unable to take his place in the dugout to see Robert Lewandowski equal his longstanding record of scoring in each of Bayern's first 11 home league games in a season.
The 72-year-old's illness did not stop him watching a 2-1 victory that leaves Bayern 18 points clear at the top of the table, however, according to Hermann.
"I think Jupp Heynckes was most engrossed in front of the TV," Hermann said.