BERLIN, April 18 : Bayern Munich forward Serge Gnabry will be out of action for weeks with an adductor muscle tear, the club said on Saturday, with the player set to miss the Bavarians' key Champions League and German Cup matches this month.  The injury could also affect the 30-year-old's chances of making the Germany squad for the World Cup starting in June. Gnabry was in the starting lineup for both the recent friendly internationals against Switzerland and Ghana in March. "FC Bayern Munich