[tnfoto]

Originally Posted by RUKen

The photo was taken by a Chicago Daily News photographer when the Phillies were in Chicago. Doyle and Van Buren are in the picture, and they were acquired from Brooklyn on April 30, 1904. Brackenridge (also spelled Breckenridge) is in the picture, and his release from the team was reported in The Sporting Life on June 11, 1904. The only visit of the Phillies to Chicago during that interval was May 11-15, 1904, when Keister was no longer with the team.

There are two pitchers who were with the team in mid-May who aren't identified as being in the group photo. One was Tom Barry (below, center), and the other was John McPherson (below, right). I think it's McPherson:

Originally Posted by cinemaodyssey

One more possibility for the aforementioned mystery player is She Donahue...

It's McPherson.