 The imposing form of first-choice keeper Antonios Nikopolidis and the presence of Józef Wandzik, Kostas Chalkias and Mario Galinović kept Kotsolis most of that time at the bench.He made his professional debut for Panathinaikos on 13 April 1999, in a Greek Cup game against Athinaikos.In 2005, he was transferred to AE Larissa where he made a total of 121 appearances, playing there until June 2009.