Kammala wannan jumla: Kottas ya kasance memba na 'yan wasan matasa na Girka. Tare da 'yan wasan matasa na Girka, ya taka leda a 2012 FIBA Turai Under-16 Championship, da kuma duka 2013 da 2014 FIBA Turai Under-18 Championships. Ya kuma taka leda a
2015 FIBA Under-19 gasar cin kofin duniya, 2015 FIBA Turai Under-20 Championship, da kuma 2nd division 2016 FIBA Turai Under-20 Championship Division B, inda ya lashe lambar tagulla.