The jersey is a thowback to 1942.
“Wartime sleeve patches were worn by all levels of professional baseball teams between 1942 and 1945. A “Health” patch, as seen here, was worn during the 1942 season, part of a war-time health and fitness awareness campaign, and from 1943-1945 a “Stars and Stripes” patch was worn.”
http://blog.heritagesportsart.com/20...-team.html?m=1