I have done some research on this a while ago. I have not reached a conclusion, but have some ideas. One resource is that the Cardinals have a museum and the folks there have been helpful on topics like these.
Check out this 1928 Cards jersey.
http://www.huntauctions.com/live/ima...=381&lot_qual=
Note that this is the only non-Rawlings jersey you will see worn by the Cards. There have been several of this type that surfaced and the prevailing view is that this is a game worn jersey (although photo matches have not yet been found). How does this impact your photo? What I wonder is whether the Cards ordered Rawlings and Saenz jerseys that year and decided to stick with Rawlings and did use the others. Again, I have no direct proof, just a thesis.
dan