Arsenal’s highly-regarded midfielder Ainsley Maitland-Niles could be out for as long as two months after suffering a “small fracture” to his left leg, the club said Thursday.

The 20-year-old – a member of the England side that won the U20 World Cup last year – suffered the injury in a challenge with Kuyle Walker during Arsenal’s opening Premier League clash against champions Manchester City, a 2-0 defeat last Sunday.

It is a blow both to the player and the club as big things had been expected of him at first team level this season in manager Unai Emery’s first campaign in charge.

“Ainsley has sustained a small fracture to his left fibula and will be out for six to eight weeks,” Arsenal said on the club’s official website.

Better news for Emery if that he could be in a position to consider selecting left-back Nacho Monreal and Danny Welbeck for the daunting trip to London rivals Chelsea on Saturday as both are back in full training.

The longer-term injured defensive duo of Bosnian international Sead Kolasinac and club captain French veteran Laurent Koscielny are improving too.

The former is likely to return to training from his knee problem in October, while Koscielny is continuing his recovery from Achilles surgery which cost him his place in the World Cup finals squad and ultimately a winners medal.