I chose "other," and my vote goes to a little-known player, who never played in the minors, let alone the bigs.
Charles Thomas was an African-American student athlete at Ohio Wesleyan Univerisity. He was the starting catcher on the school's 1904 squad. On a road trip to play against the University of Notre Dame, the team went to check into the Oliver Hotel. Although arrangements have been made well in advance, the room clerk will not allow Thomas to check in. He suggests that Thomas should seek shelter at the town's YMCA. Ohio Wesleyan's team manager checks the YMCA to see if there are enough rooms for the entire team. There aren't. Humiliated, Charles Thomas is in tears and tells teammates he will return to school.
A teammate steps up and convinces the room clerk to allow Thomas to stay in his room until a colored family in town can be found to let Thomas spend the night with him. Once allowed up to the room, the teammate locks the door and refuses to let anyone come for Thomas. Thomas's plight weighs heavily on his teammate, and will stay with him the rest of his life. He remembers Thomas sitting on the room's bed repeating "Black skin, black skin. If I only could rub it off and make it white."
The teammate? Branch Rickey. Clarence Thomas was Rickey's impetus to his efforts to break the color barrier. And therefore I believe his influence on the game of baseball is second only to Jackie Robinson.
