The 30-year-old Gee signed with the Royals in December after six seasons with the New York Mets and went 8-9 with a 4.68 ERA in 14 starts and 19 relief appearances. He is 48-46 with a 4.13 ERA in his big league career.
Nava, 33, signed with the Los Angeles Angels in December and was traded to the Royals in August. He hit .223 overall with one homer and 13 RBI in 138 at-bats. Nava has also played for Boston and Tampa Bay during six seasons in the major leagues, compiling a .262 batting average with 25 homers and 185 RBI.