Emerson was diagnosed with a small fracture in his foot Tuesday and will wear a protective boot for two weeks, Ryan Divish of The Seattle Times reports.
Emerson will likely be sidelined for about a month, as he'll require some time to get back up to speed after the boot is removed. The 18-year-old is one of Seattle's top prospects and has an .855 OPS in 93 plate appearances at Single-A Modesto this year.