The England midfielder has been sidelined for the last 12 months with an ankle problem before requiring a minor knee operation in May.
It had been thought that the 20-year-old could return in time for the start of the new Premier League season, but Wenger admits the Gunners are unlikely to be able to call on the midfielder until October.
“Hopefully, we will get Wilshere back playing for October,” said Wenger. “With Abou Diaby returning, it will be like signing two new players. The squad will be strong and competitive.”
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