Per Mertesacker to miss Arsenal's Champions League opener with Dinamo Zagreb but could return for Saturday's London derby at Chelsea.

The 30-year-old has missed Arsenal's last three matches against Liverpool, Newcastle and Stoke City with a virus and is not yet ready to make his return to action. Mertesacker, however, trained with the rest of the first-team squad on Tuesday and Sky sources understand he could feature for Arsenal in their clash with Premier League champions Chelsea at Stamford Bridge. Arsenal have not