Sosa started his career with Atlanta, debuting in Primera División on July 30, 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 December 22, 1940 v Independiente, playing a total of 40 games with the club. At his arrival to Boca Juniors, Sosa played several matches in lower divisions until he was promoted to the first squad in 1941, being part of a memorable midfield line along with Ernesto Lazzatti and Natalio Pescia. At the end of the year 1951, he left for France to play with RC Paris and Red Star, where he ended his career in 1958. He played a total of 271 matches with Boca Juniors, also scoring 7 goals. With the Xeneize Sosa also won six titles, including two Primera División championships. Sosa left Boca Juniors after 10 years in the club, being replaced by Francisco Lombardo. Sosa continued his career in France when he joined Racing Club Paris. Sosa stayed here for seven years, playing as inside forward and central midfielder.
Managerial career
After retiring from football, he became manager, coaching Boca Juniors in 1960, nut after matchday 10 of the championship in July –4 wins, 5 draws, 1 defeat, 17-9 goals– he resigned because of the unsuccessful results. José D'Amico, who later was later also coach of the national team for several matches, followed him in office. Sosa was also manager of San Telmo and Uruguayan club Racing Club de Montevideo.
Playing style
Sosa was a skillful player with good ball control, which allowed him to advance to the rival goal in attacking positions. He also had a strong shot so he was in charge of the free kicks on the right side of the field. Despite his abilities, Argentina's coach, Guillermo Stábile, did not called him up for the national team. Some versions state that he considered Sosa "dribbled excessively", preferring more aggressive players for defensive positions, such as Norberto Yácono or Juan Carlos Fonda.
