In mid-1883, Walker left his studies at Michigan and was signed to his first professional baseball contract by William Voltz, manager of the major league Toledo Blue Stockings, a Northwestern League team. As a former sportswriter for the "Cleveland Plain Dealer", Voltz watched Walker play for Oberlin; his signing reunited Walker with his former battery-mate Burket. Though Walker hit in decent numbers, recording a .251 BA, he became revered for his play behind the plate and his durability during an era where catchers wore little to no protective equipment. The Blue Stockings' ball boy recalled Walker “occasionally wore ordinary lambskin gloves with the fingers slit and slightly padded in the palm; more often he caught barehanded”. Nonetheless, he played in 60 of Toledo's 84 games during their championship season. At the core of the team's success, one sportswriter at "Sporting Life" pointed out, were Walker and pitcher Hank O'Day, which he considered “one of the most remarkable batteries in the country”.