Bayern Munich are reportedly chasing Hoffenheim striker Andrej Kramaric as a backup to Robert Lewandowski after the Croatia forward scored twice against them in last weekend's shock Bundesliga defeat.

German daily Bild claim Munich sports director Hasan Salhamidzic contacted Kramaric's management after the Croatian striker netted twice in Bayern's 4-1 loss at Hoffenheim.

It was the European champions' first defeat after 23 straight wins.

So far, Bayern are tight-lipped about the Croatia international, who has scored 67 goals in 134 Bundesliga games.

"I don't currently know anything about that," said Bayern head coach Hansi Flick when asked about the Kramaric rumours, "but I know him very well, he is one of the best strikers in the Bundesliga and has enormous quality."

Bayern routinely buy the German league's best players and Kramaric is the man of the moment.

He has netted seven goals in just three games: a hat-trick against Cologne on the opening day of the Bundesliga season, two goals in the German Cup win over minnows Chemnitz and another double against Bayern.

According to reports, Hoffenheim want at least 40 million euros ($47 million) for Kramaric, who has no buy-out clause in his contract which runs until 2022.

However, Germany legend Lothar Matthaeus has already urged Bayern to sign the 29-year-old before the transfer window closes on Monday.

"He would not only be an ideal backup for Robert Lewandowski, but also for (attacking midfielder) Thomas Mueller. (Kramaric) is a good professional with a lot of quality," said the Sky pundit.