Arsenal midfielder Alex Oxlade-Chamberlain faces at least three months on the sidelines, dealing a blow to the team’s early-season hopes.

The England international injured his left knee in Arsenal’s Premier League opener on Saturday which ended in a 3-1 loss to Aston Villa.

Manager Arsene Wenger said Tuesday that Oxlade-Chamberlain has a posterior cruciate problem – “a ligament which is stretched”- but he is not expected to require surgery.

Wenger said Oxlade-Chamberlain was facing at least six weeks out, but the player later said he faced a lay-off twice as long.

“Gutted i’m injured so early in the season,” Oxlade-Chamberlain wrote on Twitter. “But I’m going to be working hard to hopefully be back playing in 3 months.”

Oxlade-Chamberlain seems likely to miss England’s key World Cup qualifiers in September and October, and a potential playoff in November.

More immediately, he is out of Arsenal’s Champions League playoff against Fenerbache, which starts in Istanbul on Wednesday.

He will also be sorely missed in the Premier League, especially after Arsenal opened the season by losing to Aston Villa on Saturday.