Sky Sports Germany reported that the 38-year-old will miss the Bundesliga club's next four games, including the second leg of the Champions League tie at Leverkusen.
Manuel Neuer announced his retirement from internationals on Wednesday after playing 124 times for his country since 2009.
Harry Kane scores twice as Bayern Munich beat Eintracht Frankfurt 3-2 to go nine points clear in the Bundesliga; Monaco stun Lens in Ligue 1.
'We won all the matches in pre-season and we want to carry this into the Bundesliga season next week.'
Neuer is the second Bayern player to be ruled out for months after France international Lucas Hernandez tore a knee ligament in the defending champions' 4-1 win over Australia in their World Cup Group D match last month.
Real Madrid ended a turbulent week with a 2-0 LaLiga win over lowly Levante on Saturday courtesy of second-half goals from Kylian Mbappe and Raul Asencio.
Inter edge Genoa to go top
Neuer, David Alaba, Jerome Boateng and Thomas Muller were a part of the Bayern Munich squad that won the Champions League in 2013, defeating Borrusia Dortmund in the final.
Schalke 04 goalkeeper Manuel Neuer was praised by Manchester United manager Alex Ferguson despite conceding two goals in two minutes during Tuesday's 2-0 Champions League semi-final second leg defeat.
Goals from captain Kylian Mbappe and Michael Olise earned France a 2-0 victory over Germany in Stuttgart on Sunday.
Neuer made the squad despite playing in just one official game, a friendly against Austria on Friday, since breaking a bone in his foot in September but talented 22-year-old Sane was the biggest name to miss out.
Manuel Neuer became the first goalkeeper since 2002 to make the final short list for the FIFA world player of the year award on Monday when he was included alongside Cristiano Ronaldo and Lionel Messi in the final three.
A summary of Wednesday's action in the UEFA Champions League.
Thomas Mueller bid farewell in his final home game after 25 years at the club.
World Cup winner Neuer, who has been the Germany number one for more than eight years, has not played a single official game since breaking a bone in his foot back in September but Koepke said he was fully on track for the tournament in Russia.
"We have a clear position. I will see how this develops and we will discuss it with the other nations from Europe. We expect to be allowed to wear the (One Love) armband," he said.
Bayern Munich slumped to a shock home defeat by Borussia Moenchengladbach in their opening Bundesliga match on Sunday following a blunder by their most expensive new signings.
Bayern Munich made it 16 wins from 16 games this season to underline their credentials as early Champions League favourites, beating holders Paris St Germain 2-1 away as Luis Diaz scored two goals and was shown a red card on Tuesday.
News of all that's transpired on and off the football field
IMAGES from matches played across European leagues on Saturday
Germany goalkeeper Manuel Neuer is ready to play the mentor's role irrespective of who leads the team in their Euro 2016 opener against Ukraine on Sunday.
So, who in your opinion, dear readers, is your favourite to win the prestigious prize at the ceremony in Zurich on January 12? Take your pick and vote now!
News of all that's transpired on and off the football field
Joao Neves scored twice as Paris St Germain swept aside Lionel Messi's Inter Miami 4-0 at Atlanta's Mercedes-Benz Stadium to secure their place in the Club World Cup quarter-finals.
According to the BCC, the prince has been a supporter of Aston Villa since his school days.
Star footballers Lionel Messi, Manuel Neuer and Cristiano Ronaldo, who had been shortlisted for the FIFA Ballon d'Or award, have been selected by their peers for the 2014 FIFPro World XI team.
Bayern Munich came back from a goal down to beat 10-man Augsburg 3-1 away on Friday and move nine points clear at the top of the Bundesliga, but Jamal Musiala went off injured and looks unlikely to be fit for next week's Champions League quarter-final.
Germany have only their superior fitness and world-class goalkeeper Manuel Neuer to thank for scraping past Algeria 2-1 in extra time to move into the World Cup quarter-finals after doing almost everything wrong over 90 minutes.
Barcelona captain Raphinha scored twice as they returned to winning ways in LaLiga for the first time in a month with a 5-1 victory at Mallorca on Tuesday.
Joshua Kimmich named new Germany captain after Gundogan's retirement, the national team's coach Julian Nagelsmann announced on Monday.
Germany coach Julian Nagelsmann made two changes to his line-up with Jonathan Tah and Emre Can coming in to the team to face an unchanged Spain in their Euro 2024 quarter-final clash on Friday.
Germany are banking on a mix of hugely talented young players, including Jamal Musiala and newly-crowned Bundesliga champion Florian Wirtz, and experienced veterans such as 2014 World Cup winners Manuel Neuer, Thomas Mueller and Toni Kroos.
Images from the Euro 2024 quarter-final between Spain and Germany, at Stuttgart Arena, Germany, on Friday.
Neuer sidelined for 'coming weeks' after knee surgery - Bayern
Germany coach Julian Nagelsmann -- who for the third time named the same starting 11 -- is a big fan of Havertz, but the fact an old-school number 9 like Fuellkrug saved the day may prompt calls for the side to have a clear focal point up front.
A summary of Tuesday's Champions League first leg quarter-finals between Arsenal and Real Madrid, and Inter Milan and Bayern Munich.
World soccer body FIFA had threatened seven European teams with sporting sanctions if they wore it at the World Cup with the federations backing down.
Manuel Neuer remained Germany's number one and captain, even as they underperformed in the UEFA Nations League and Euro 2020 qualifiers.
The 1-1 draw leaves Germany facing a must-win match against Costa Rica.
Moukoko won a surprise call-up this month after having scored six goals in the league for Borussia Dortmund.