Arsenal midfielder Jack Wilshere is likely to miss this weekend's Premier League opener and could face up to three weeks on the sideline, sources told ESPN FC.
Wilshere, 23, picked up an ankle injury in training on Saturday and was left out of the squad that beat Chelsea 1-0 in the Community Shield at Wembley on Sunday.
Arsenal manager Arsene Wenger said in his news conference after the match that he only expected Wilshere to be out for "days," but sources say the England international is highly unlikely to recover in time for the London derby against West Ham at the Emirates Stadium on Saturday.
Press Association earlier reported that Wilshere was set to miss the West Ham match, and sources told ESPN FC that he will also miss the following match against Crystal Palace -- and faces an uphill battle to to be fit for the game against Liverpool on Aug. 24.
Should the ankle problem persist, Wilshere could also be a doubt for England's Euro 2016 qualification doubleheader against San Marino and Switzerland on Sept. 5 and 8.
Wilshere was fit for Arsenal's run-in last term, which saw them finish third in the Premier League and retain the FA Cup, and scored twice in England's 3-2 European Championship qualifying win over Slovenia in June.
He made just 14 Premier League appearances last season, missing almost six months of the campaign after undergoing ankle surgery last November and then a related follow-up procedure in February.
The Gunners youth product has a history of ankle and foot problems that have limited him to just 100 Premier League appearances since making his debut for the club in September 2008.
Information from Press Association was used in this report.