Kotsios started his career from the youth department of Ikaros Neapolis, a clb based in Larissa.
After two years he moved to Iraklis Larissa and he was recommended to OFI Crete by his Ikaros Neapolis coach Ilias Selionis,[1] also an ex-player of the Cretan club.
He first worked with renowned Dutch coach Eugene Gerrard and stayed with OFI for 8 seasons before signing for Panathinaikos.Kotsios stayed with Panathinaikos for 3 years and in 2007 he returned to his hometown club Larissa playing in the UEFA Cup.
On 2 November 2005 Pnathinaikos were defeated by Barcelona with 5-0 in the UEFA Champions League in Lionel Messi.
[2] After the end of the game Kotsios swapped jerseys with the 18-year old then Lionel Messi who scored his first ever goal in Europe.