I pick up any book I can find that has images of 19th century players. Fortunately I've got a good memory for faces and patterns (not so much for actual facts), so any time I see a 'familiar face' in an old image, I go back to my library and start digging.
None of these faces look familiar, but the technique does work. I once owned a tintype of a man who appeared to be a baseball player, but had no equipment. I sold it for $75. Later I located his uniform on a hall-of-famer. Although I was never able to i.d. the player, it was an 1860's tintype of a player who played professionally
I recommend locating the two SABR publications on 19th century stars.