Seymour subsequently signed as a free agent with the Boston Braves on February 25, 1913. After playing sparingly for the Braves during the 1913 season, the Braves released him on July 19, 1913, as they were carrying 26 players on their roster, though league rules permitted a maximum roster of 25. Seymour played for the Buffalo Bisons of the Class-A International League after being released by the Braves. He returned to professional baseball in 1918, playing in 13 games for the Newark Bears of the International League.