Arsenal defender Thomas Vermaelen had ankle surgery and will be sidelined for a month, ruling him out two Champions League matches and four English Premier League games.

Vermaelen, 25, missed most of last season with an Achilles injury and required minor surgery that will cost the center back more time this season.

"Thomas Vermaelen is expected to be back in training with the first-team squad in around a month," Arsenal posted in a statement on its website Tuesday.

"Vermaelen has undergone a minor procedure to remove an inflamed plantaris tendon from his left ankle. This is the same treatment that he had on his right ankle in January this year and has nothing to do with his Achilles tendon.

"The action was taken after consultation with specialists who advised this was the best thing to do to prevent it becoming a persistent problem."

The injury is another blow for Arsenal, which has struggled early this season after the transfers of midfielders Cesc Fabregas to Barcelona and Samir Nasri to Manchester City.

Arsenal starts Group F of the Champions League against Borussia Dortmund in Germany on Sept. 13 and hosts Greek side Olympiacos on Sept. 28.

The Belgian international is also expected to miss league matches against Swansea City, Blackburn, Bolton and Tottenham.