Heynckes caught napping by Bayern's Schalke win

Jupp Heynckes slept through the start of Bayern Munich's Bundesliga win over Schalke last weekend as he recuperated from a bout of the flu.

The veteran head coach left the first team in the hands of Peter Hermann and Hermann Gerland and goals from Robert Lewandowski and Thomas Muller secured a 2-1 victory for the runaway league leaders.

Speaking at a news conference ahead of Saturday's trip to struggling Wolfsburg, Heynckes revealed he missed Lewandowski's early opener.

Asked whether the unplanned absence had given him chance to think about his future after this season, the 72-year-old replied. "When I'm in bed I try to sleep and I don't try to think about anything.

"Last Friday, I didn't feel well in the press conference and then I felt dreadful after that.

"On Saturday, I went to bed at 4:15 and I woke up past seven o'clock. Bayern and Schalke was already on and I'd missed the first half-hour. It was very embarrassing, I felt awful."

Heynckes reported a strain of flu remained in the Bayern camp, although he does not expect any absentees through illness at the Volkswagen Arena.

Upon his return, the veteran tactician gave his squad some tips with regards to avoiding ill health, although he fears his words may have fallen on deaf ears.

"Preventing illness means taking vitamins and you shouldn't go outdoors with wet hair after training or dressed too lightly. You have to dress warmly, of course," he explained.

"After the game when the immune system is a little weaker you have to be particularly careful – and not just run around with a little training jacket.

"There are a lot of little things that you have to take into consideration. But you know how young people are when the old people give them advice. You know how it is with your children – young guys don't listen.

"If you're a strict mum or a strict dad then sometimes the kids listen but if not… I'm not sure I convinced them."

One man with a more serious fitness concern in midfielder Renato Sanches.

The Portugal international has endured underwhelming loan stint at Swansea City this season and Heynckes confirmed he returned to Munich this week for treatment on a hamstring injury.

"I heard that he was here but I communicate with [sporting director] Hasan Salihamidzic all the time. He took care of the situation," he added.

"He talked to Renato's agent and then he talked to the player. He arranged an appointment with Dr Muller-Wolfahrt. That's why Renato Sanches was in Munich.

"He's a very important man and it's no secret that he is here. You want to take care of your players because he is still owned by us."