Martin left Arsenal in 2013 after three seasons with the club.
The Swiss centre back joined the Gunners' academy from Grasshoppers via a spell at Zurich and progressed into the reserve side, making 22 appearances in 2011/12.
Martin was then promoted to the first team in 2012 and made his debut when he started against Coventry City in the League Cup, before coming on as an 83rd-minute substitute against Olympiacos in the Champions League.
The tall defender found playing time hard to come by, though, with Laurent Koscielny and Per Mertesacker just two of the names ahead of him, so he joined 1. FC Nuremberg on a free transfer at the end of his contract.