With the departure of Lewandoski, many expect Bayern bring in a proper no. 9. Although Mane isn’t a like-for-like option but I am convinced that he is going to score many goals and almost replace Lewandoski. He might be deployed as a speedy target man, something similar to Jamie Vardy at Leicester City and Kylian Mbappé at PSG. Mane has proven that he can score from all over the pitch, with his decisiveness in front of goal from wherever he operates. So I strongly believe that he can excel as a no. 9, and there is little or no doubt that he'd be great at the job in Lewandoski’s absence.
Next season Bayern already have Sadio Mane as a new player who was brought in this summer, Sadio Mane and Thomas Muller can certainly trouble the opponent's defense. I saw when Sadio Mane was at Liverpool he was an active player providing assists and scoring goals. finishing very well and often a goal. Moreover, in the Bundesliga, the competition is not as tight as the Premier League, which is why he can score more goals next season, maybe I will think Sadio Mane can score 20 goals in his first season with Bayern Munich.
Mane is a professional player. He may or may not be the replacement for Lewandoski. But his energy and relentless pressing will fit in seamlessly with Nagelsmann's style of play. They have some quality players already in the team so I expect a whole good season. Mane can form partnership with either Muller, Gnabry or Sane like he did with Mo Salah and Firmino in Liverpool. His flexibility is a major bonus for his manager. Mane can play as a false 9, and is also equally adept on either side of a 4-3-3 - a concept that Nagelsmann has been toying with for quite some time.