Koumantarakis scored his first domestic league goal for his new club on 5 August in the away game in the Charmilles Stadium, Geneva as Basel played a 1–1 draw against Servette.
On 5 August, Koumantarakis scored his first domestic league goal while playing away from home for Basel in a 1–1 tie against Servette at the Charmilles Stadium in Geneva.