Niko Kovac has a "mountain of problems piling up" at Bayern Munich, according to his predecessor Jupp Heynckes.
Heynckes retired at the end of last season after a fourth stint in charge of the Bavarian giants, guiding them to a sixth successive Bundesliga crown.
Former Bayern midfielder Kovac was chosen to replace him but has struggled to replicate Heynckes' success with the side lying fifth in the table, nine points behind leaders Borussia Dortmund.
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Heynckes has sympathy for the 47-year-old Croatian and admits he has to contend with a difficult dressing room.
He told the Westdeutsche Zeitung: "He is a young coach and wants to conquer the world.
"But Niko Kovac does not have it easy in Munich. There are good guys there and there are divas, and then there are serious injuries to important players.
"There are a mountain of problems piling up."
Speculation in Germany suggests Kovac could be sacked this week, irrespective of how Bayern get on in Tuesday's Champions League tie with Benfica.
The Croat is not about to throw in the towel, though, and has vowed to fight for his future.
He told reporters after a shock 3-3 draw at home to Fortuna Dusseldorf on Saturday: "Those who know me know I'm always a fighter.
"My whole life I have had to fight. The words 'give up', 'raise the white flag' do not exist in my vocabulary.
"Criticism is always there if you don't meet the demands that this club naturally has. We only need one point [to reach the last 16], but we want to win."