"It's like every year, no one really knows where he stands," the 47-year-old said in a press conference reported by the club website.

"(You should not) overvalue the results of the preparatory games. A lot of work is waiting for us on Friday.

"But we play at home, we have the first game of the Bundesliga season and, of course, want to end this with a win. We want to win the title."

The Croatian boss will be without new signing Ivan Perisic after the striker was ruled out through a yellow card suspension carried over from his time with Serie A club Inter Milan.

Also sidelined for the Bavarians is Spain's Javi Martinez, who has yet to train with the team after picking up a knock.

In the previous meeting between the two sides Hertha managed a narrow 1-0 victory over Bayern, but in the four meetings before that the Bavarians were unbeaten.

Hertha general manager Michael Preetz believes his side will need to produce something special to beat last year's champions.

"I don't even know if there is a team that has caused Bayern difficulties in recent years. We are possibly one of them," he said.

"We know that we need an exceptional performance."

Hertha's new coach Ante Covic was just as cautious, adding: "If you play away against the German champions, you have the heaviest opponent before the start on the first match day.

"Still, the anticipation is great when you open the season and we all start from scratch."