Soccer was not as hard-hit as some other sports, but all leagues felt the impact; in fact the Čechie team of Chicago lost every member of its roster to enlistment.
Many soccer organizations launched fund raising campaigns and benefit matches to raise money to provide support for U.S. soldiers through, among other means, the provision of soccer equipment and gear to enhance their recreational opportunities.
One such project was the Soccer Football Chain Letter Fund launched by Thomas Cahill and the USFA.
[1] Other welcome events included record attendance figures in some late-round games of the National Challenge Cup that were well promoted.
At the time the laws did not specifically allow nor outlaw substitutes per se, but the consensus was that eventually they would become a reality.