The team made the announcement Monday, but would not say if he needed surgery or how long he will be out.
On Sunday, the team announced he had a separated shoulder, but an MRI upon returning to Charlotte confirmed additional a torn labrum too.
The Hornets say Kidd-Gilchrist will meet with team orthopedist Dr. Marcus Cook on Tuesday to determine the next steps for the recovery and rehabilitation of his shoulder.
Kidd-Gilchrist suffered the injury in Saturday's preseason game at Orlando in the second quarter when he landed on the floor.
Charlotte was 28-29 last season when Kidd-Gilchrist played and 5-20 without him.