Bayern Munich forward Serge Gnabry is sidelined “for the time being” with a muscle strain and will definitely miss next weeks’s Champions League quarter-final return leg against Arsenal. Gnabry scored the 1-1 equalizer in Tuesday’s 2-2 draw in London before having to leave the pitch injured in the 71st minute. “Bayern must do without Serge Gnabry for the time being. The winger suffered a muscle strain in his left hamstring … as confirmed by a scan by the Bayern medical department,” a club statement Wednesday said. Coach Thomas Tuchel said post-match that Gnabry will not be able to play in th…