Okpala, 23, is 6-foot-8 and has spent all three years of his NBA career with the Heat, including last season, when he appeared in 21 games.
He was traded to the Thunder in February and then waived shortly thereafter.
While Haynes and Mintz didn’t specify, Okpala likely received a partially guaranteed deal to join the Kings. As Haynes noted, Okpala did play under new Sacramento coach Mike Brown with the Nigerian national team.
The Kings have had an interesting offseason. Along with hiring Brown as coach, they landed former Iowa forward Keegan Murray with the No. 4 overall draft pick, and signed guard Malik Monk.