Lewandowski has reached the 40-goal mark across all competitions for the third consecutive season this term, netting 40 times in 46 games - including 29 in as many Bundesliga outings - to help his side to the brink of a domestic double and the Champions League semi-finals.
However, speculation has been growing that the Poland international is considering his options at the Allianz Arena and could be open to a new challenge should the opportunity arise.
Bayern Munich have previously ruled out the sale of their most potent attacker at any price, but Calciomercato claims that the German champions have changed their stance and could now be ready to cash in on Lewandowski should a suitable offer arrive.
Madrid are considered the early favourites for the striker's signature, although former president Ramon Calderon last month suggested that Tottenham Hotspur's Harry Kane would be their number one target this summer.
Bayern are thought to be lining up an approach for Atletico Madrid striker Antoine Griezmann, whose arrival would pave the way for Lewandowski to leave the club.