Sosa started his career with Atlanta, debuting in Primera División on 30 July 1939 v Chacarita Juniors. His initial position was left back. Sosa's good performances on the field sparkled interest in Boca Juniors, which finally acquired Sosa for $25,000 plus the transfers of players Vilana, Tenorio and Angeletti. Boca also gave Atlanta the ...... of a friendly match played in Ferro Carril Oeste stadium. His last match with Atlanta was on 22 December 1940 v Independiente,Carlos Adolfo Sosa on Fútbol Factory (Archive 20 October 2007) playing a total of 40 games with the club.
