I found a couple of small items in the Indianapolis Freeman (October 23, 1909) identifying the pitcher named “Washington” who filled in for the 1909 Cuban Stars, the team for which Scott Simkus has compiled statistics.  Since Harry “Rube” Washington (“one of the best tight pinch pitchers in the country,” according to the Freeman) doesn’t appear in Riley or anywhere else as far as I can tell, I thought I’d pass along the information about him.

In 1910 Washington went on to pitch for the Oklahoma Monarchs
of the Texas Colored League (a circuit I’ll have more to say about soon); he may be the “Washington” Riley lists as
pitching for the St. Louis Giants that year (though I haven’t confirmed
that yet).