Hardly conclusive but adding to the intrigue...This from a 2014 Ebay auction:
Rare c. 1913 felt pennant from the Oakland Oaks Baseball Team. Measures a 29 inches across and condition is VERY nice. From the collection of a 1908-1915 Minor League Baseball Player from the era and I have a couple other pennants including an Centralia pennant and a pictoral Aberdeen Washington pennant as well! There are no specific markings identifying it as baseball but most pennants of the era were like this. Considering the collection it came from I have NO doubt this was used by a baseball fan to root on the Oakland Oaks, especially since dark blue and white were the Oaks colors as well!
