Arsenal defender Laurent Koscielny has returned to training to help ease Arsene Wenger's central defensive concerns ahead of the season-opener against Crystal Palace.

The France international was substituted at half-time of Sunday's comprehensive 3-0 Community Shield win over Manchester City with an Achilles problem.

But Koscielny is back in training and could still be available for the Saturday's clash against Tony Pulis' side.

Training day: Laurent Koscielny (left) has given Arsenal a timely boost by returning to full training

Cometh the hour... Koscielny has a knack of scoring crucial goals, and equalised in May's FA Cup final

Without Koscielny, Wenger would face something of a dilemma in central defence.

His only other established central defender, Per Mertesacker, just started pre-season training on Monday following Germany's World Cup success.

Limited options: Per Mertesacker is only just back in training and Nacho Monreal is a left back by trade

Calum Chambers has played at centre back in all three of his pre-season appearances for the Gunners since his £16million arrival from Southampton and looks set to feature in the heart of Arsenal's defence on Saturday.

Nacho Monreal, who is a left back by trade, could be used as a makeshift centre back if Wenger decides not to risk Koscielny or Mertesacker ahead of next week's Champions league qualifier against Besiktas.