WATCH: Per Mertesacker Leaves After Gary Cahill's Elbow Strikes Face

The Arsenal defender had to be substituted out after taking a bloody hit to his face.

Arsenal defender Per Mertesacker had to be substituted during the Community Shield after being struck by the elbow of Chelsea defender Gary Cahill.

As the duo went up for a header, the former Germany international came off the worse and was treated on the pitch for a nose injury before making way for substitute Sead Kolasinac.

New Gunners signing Kolasinac came on in place of the ex-Werder Bremen centre-back, with Nacho Monreal moving to the centre of Arsenal's back three.

With Laurent Koscielny currently sidelined with a ban following his red card at the end of last season against Everton, Arsenal manager Arsene Wenger is now stretched for options at centre-back ahead of their first Premier League match against Leicester on Friday.

Gabriel Paulista is currently out with a medial collateral knee ligament injury, meaning Kolasinac and Monreal could both line up in a back three alongside Rob Holding when the Foxes travel to the Emirates next week.