30-year-old Greek international Sokratis Papastathopoulos joined Arsenal from Borussia Dortmund. The hugely-experienced defender who won the German Cup in 2017, played in a number of clubs such as Werder Bremen, AC Milan, Genoa and AEK Athens.
In Arsenal his shirt number will be No 5.
The No 5 shirt was worn most famously by David O'Leary during the 1980, as well as Martin Keown during the Invicibles era, as well as Kolo Toure and more recently Thomas Vermaelen. The shirt was vacated when Gabriel Paulista left the club last summer.