A. S. Valentine was an early professional football player for the Allegheny Athletic Association. He served as the team's quarterback in 1890 and 1891. However, he jumped to the rival Pittsburgh Athletic Club in 1892. Valentine played for Pittsburgh in their first two games. Then, without warning, he suddenly jumped back to the Allegheny team. Some Pittsburgh A.C. members accused Allegheny of enticing him back, while others charged he had all along been a spy for them. During Allegheny's two games against the Pittsburgh A.C. that year, Valentine played as a left halfback. In 1891, he played in a game for Shadyside Academy as that team was defeated by the Pittsburgh A.C., 26?0. That same year, he scored a touchdown against the Greensburg Athletic Association, during a 10?5 Allegheny win. During a game against the Detroit Athletic Association on November 11, 1893, Valentine reportedly openly punched Detroit's quarterback so openly. The officials ignored the incident, and the Detroiter used the next play to retaliate against Valentine. Shortly after, a brawl between the two clubs erupted. Allegheny would go on to win the game 18?0.