The Royals transferred Seabold (lat) from the 15-day injured list to the 60-day IL on Monday.
Seabold will give up his spot on the 40-man roster to right-hander Nolan Hoffman, whom the Royals acquired in a trade with the Phillies. Since Seabold was initially placed on the IL on July 1, he won't be eligible for activation until Aug. 30. Seabold is currently rehabbing in Arizona while he recovers from the right lat strain, and a potential target date for his return likely won't be known until he heads out on a rehab assignment.