Jack Wilshere
Arsenal midfielder Jack Wilshere is set to miss Arsenal's opening game of the season after picking up an injury during trainingGetty

Arsenal have been reportedly handed a massive blow ahead of the start of the new Premier League campaign after Jack Wilshere suffered an ankle injury during training, according to a report in the Daily Mail.

The English midfielder missed the north London club's victory over Chelsea in the Community Shield on Sunday, 2 August after he picked up a minor knock during training the previous day and could be reportedly sidelined for up to three weeks.

Arsene Wenger played down the injury when he spoke to the media following the game, and revealed that it was just a matter of days before the England international returned to action.

"He couldn't take part in the game today because of an ankle problem he sustained yesterday. It happened at the training ground. We don't think it's bad at all but I haven't been told whether it will be two days or five days. I don't know how long he will not be available for. It's a matter of days," Wenger said, as quoted on Arsenal's official site.

This will come as a big blow for Wilshere, who was reaching peak fitness after missing a large part of the 2014/15 season after going under the knife for an ankle injury he sustained against Manchester United in November last year.

The French manager was hoping that the midfielder go a full season without injury and showcase his true potential. But this will be a setback in his preparations for the upcoming campaign, with the report claiming that Wilshere could miss the first three weeks of the season, ruling him out of the opening two games against West Ham United and Crystal Palace.

Apart from the Premier League games, the 23-year-old midfielder could also be a doubt for England's Euro 2016 qualifier double-header against San Marino and Switzerland.