The 31-year-old hit 30 goals in 25 games for Bayern in the first half of the season, including 10 goals in the Champions League group stage.

Lewandowski's tally is all the more remarkable given that he played the last few weeks before the winter break with a groin injury, which was operated on last month.

Bayern sit third in the Bundesliga, four points behind leaders RB Leipzig, as the league resumes this weekend.

Lewandowski missed Bayern's warm-weather training camp in Qatar earlier this month to work on his fitness in Munich.

"He is nearly at 100 percent, he worked hard on his fitness while we were in Doha, is in good condition and he is pain-free, which is the main thing," Flick said on Friday.

Lewandowski could break Gerd Mueller's Bundesliga record of 40 goals in the 1971/72 season, having scored 19 in 17 games so far.

Bayern lost 2-0 on their last visit to Berlin's Olympic Stadium in September 2018 and Flick expects another tough encounter against Hertha, coached by ex-Bayern boss Jurgen Klinsmann.

"I know Jurgen will wind his team up, that is his quality," said Flick, who is in charge of Bayern until the end of the season.

"We want to create many chances and score our goals early."

Flick expects Philippe Coutinho to be crucial to Bayern's chances of unpicking the home defence.

"Coutinho's understanding within the team is constantly improving and against tight, compact teams it is important to be able to fall back on that," Flick added.

Bayern finished 2019 with four straight wins after back-to-back league defeats by Bayer Leverkusen and Borussia Moenchengladbach.

Bayern's seven-year domination of the Bundesliga is in danger of finally being broken, with second-placed Moenchengladbach two points above them, and Borussia Dortmund only seven points off leaders Leipzig in fourth.

"It's clear that one or two things haven't worked," admitted Flick. "But the team knows what they need to do and are experienced enough to implement it."

Flick refused to rule out making signings this month, especially as Bayern are light on defenders with Niklas Suele and Lucas Hernandez sidelined by long-term injuries.

"I have had a good conversation with (sporting director Hasan) Salihamidzic on the subject and the most important thing is that any players who come must be able to take us further."

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