France right back Mathieu played much of his football back in his home country last season, during a loan spell with Ligue 1 side Bordeaux.
He started the season with Arsenal, playing seven games - including the League Cup win over Tottenham at White Hart Lane - before joining Bordeaux on the winter transfer deadline day. Injury restricted him to just nine league appearances at Bordeaux, as he helped them to a mid-table finish.
This is Mathieu's third season with the Gunners. Previously he enjoyed 18 months with Newcastle United after arriving in the Premier League from Lille, where he played more than 300 games in all competitions.
He won the league and cup double (2010/11) during his nine-year association with the French side, and the following season was named in the Ligue 1 Team of the Year.
An attack-minded full-back who is tenacious in the tackle and full of running, Mathieu brings a wealth of experience to the Gunners’ back four.
A full France international since November 2011, the athletic full back was ever-present at Euro 2012 and also featured heavily at the 2014 World Cup in Brazil.