Because the Federal League was officially an Outlaw League, players who bolted from contracts in the organized leagues could be suspended or banned completely. Many of the players who did so played under an assumed name to hide their actions. In addition, because the league was a new league of unknown caliber and reputation, it was an opportunity for lesser players to play professional ball. Clubs drew from local amateur teams in search of talent, with some of these players appearing in just a game or two on trial.
Below is a list of players, for whom there is only a last name in the box score. A few have be been identified from the few clues provided in the game articles, or from references later. Likely some will never be identified.
1913 Federal League players