It is thought that the player depicted in this carving is Michael J. "King" Kelly, one of the most popular players of the 1880s. Kelly had an illustrious career, playing for the Boston Reds, the Chicago White Stockings, the Boston Beaneaters and Cincinnati's Kelly's Killers, also known as the Cincinnati Reds.
For a similar example of a baseball player signed by Robb see Frederick Fried, Artists in Wood, (New York: Bramhall House, 1970), p. 213, fig. 191.