He was given his Prva HNL debut for Dinamo by coach Zoran Mamić on 7 March 2015 in a 2–0 home win over Zagreb, starting and playing the full 90 minutes.

[8] He made his European debut on 12 July 2016, when coach Zlatko Kranjčar substituted him for Alexandru Mățel in the 66th minute of the 2–1 victory over Vardar in Skopje in the Champions League second qualifying round.

[16] At the beginning of the 2021–22 season, on 7 August, Sosa captained Stuttgart for the first time in a DFB-Pokal match against Dynamo Berlin, scoring and assisting in the 6–0 victory.

[17] Seven days later, on the first matchday of Bundesliga, Sosa provided Marc-Oliver Kempf and Hamadi Al Ghaddioui with a hat-trick of assists as Stuttgart defeated Greuther Fürth 5–1.

[28] However, on 11 May, Oliver Bierhoff, the technical director of the German Football Association, announced that Sosa is ineligible to play for Germany according to the FIFA rules.

[33] On 14 November, in the crucial qualifier against the same opponent, Sosa caused Fyodor Kudryashov's own goal, leading to Croatia's 1–0 victory and qualification for the World Cup.