Okongwu has been ruled out for Thursday's preseason game against the Grizzlies, Brad Rowland of the Locked On Podcast Network reports.
Okongwu is likely simply getting a night to rest Thursday, as the Hawks didn't indicate that he's dealing with an injury. Bruno Fernando and Mouhamed Gueye could see increased playing time against Memphis, while Okongwu's next chance to play will be Saturday against New Orleans.