Walter Alston only played in only one major league game, who did he replace?

I think this is right ... initially a third baseman, he moved to first base in 1936 and led the Mid-Atlantic League with 35 homers. Promoted to St. Louis, Alston struck out in his only major league at-bat, which was played on September 27th, 1936. According to the 1936 St Louis roster the regular first baseman was Jimmy Mize.

Actually it was Johnny Mize, nice job!