Arsène Wenger confirms Arsenal’s Per Mertesacker is out for months

• Arsenal short of defensive options after German’s injury
• Knee problem means centre-half will miss start of seasonArsène Wenger has revealed Per Mertesacker will be out of action for “a few months” with a knee injury.The centre-half suffered the problem during the friendly against Lens on Friday and was left out of Arsenal’s tour of the United States. There were reports the injury would rule out the 31-year-old for up to five months but Wenger could on