Bayern Munich's Thomas Mueller is struggling to be fit for Saturday's German Cup final against Eintracht Frankfurt as he is suffering from gastroenteritis.
The 28-year-old German star missed training on Thursday while winger Arjen Robben, who has a groin strain, and Joshua Kimmich both underwent fitness tests.
With one eye on next month's World Cup, Bayern fans' main hope for the final at Berlin's Olympic Stadium is that Germany captain and goalkeeper Manuel Neuer will make his comeback after eight months sidelined by a fractured foot.
The Berlin final will be the last game in charge for both Bayern coach Jupp Heynckes and the man who is taking his job, Frankfurt boss Niko Kovac.
Heynckes oversaw his last training session in Munich on Thursday before the team flew to Berlin and the message is clear.
"If we have to say goodbye to our coach, then we want to do that with the double," said Bayern chairman Karl-Heinz Rummenigge.
The 73-year-old Heynckes took over in October for his fourth stint as head coach when Carlo Ancelotti was fired.
Heynckes could bow out with the league and cup double after Bayern won the Bundesliga title by a massive 21 points.
"We want to put in a good performance for the fans and create another highlight," said Heynckes, who was received the farewell by Bayern staff with a presentation at the Saebener Strasse training ground on Thursday.
He also offered a warning to Kovac, his replacement for next season.
"It is an incredibly labour-intensive, around-the-clock job," said Heynckes, who holds the record of 1,037 German league games as a player or coach.
"Being coach at Bayern is a great opportunity - but also a huge commitment."
However, he insists there will be no return for a fifth stint as coach.
"FC Bayern should not ask again when I'm 80, that was definitively it for me," said Heynckes.
"I will not have withdrawal symptoms and no boredom, I have a lot of hobbies."
Heynckes says he is looking forward to watching football as a fan alongside his wife Iris and dog Cando at the family home in Schwalmtal, near Moenchengladbach.
"That's what makes me happy, so it's easy for me to quit the job."