Ayon hurt his right shoulder in Tuesday night's loss at Indiana.
The Hawks have a severe shortage of players at center. They already have lost All-Star Al Horford for the season after he had surgery to repair his torn right pectoral muscle. Horford's backup, Pero Antic, is out indefinitely with a stress fracture in his right ankle.
Atlanta coach Mike Budenholzer says Elton Brand will start at center. Budenholzer wouldn't provide details on the severity of Ayon's injury.
Cartier Martin is starting for guard DeMarre Carroll, who has missed two games because of a left hamstring strain.