Bayern Munich says it is ''surprised'' by Philipp Lahm's decision to announce his retirement on his own. Bayern chairman Karl-Heinz Rummenigge says ''until yesterday we assumed that there would be a joint announcement by Philipp Lahm and Bayern Munich on this decision.'' Lahm, who has played in 501 competitive games for Bayern and helped Germany win the 2014 World Cup, said Tuesday he has decided to quit at the end of the season, one year before his contract ends, and turn down the vacant role of sporting director at the club. Rummenigge says ''we want to make clear that the doors of Bayern Munich will also be open for Philipp in the future.'' Lahm could end his playing days with an eighth Bundesliga title at Bayern.