Hernandez signed a minor-league contract with the Royals on Saturday.
The Royals reinstated Hernandez (shoulder) from the 60-day injured list Monday and optioned him to High-A Quad Cities.
Hernandez (shoulder) will begin a rehab assignment Wednesday with the Royals' rookie-level Arizona Complex League affiliate.
Hernandez was placed on the 60-day injured list Thursday, Anne Rogers of MLB.com reports.
Hernandez (shoulder) was optioned to Double-A Northwest Arkansas on Friday.
Hernandez was diagnosed with a dislocated right shoulder Sunday and is expected to be sidelined 3-to-4 months , Anne Rogers of MLB.com reports.