Guard Kris Dunn will undergo arthroscopic surgery Dec. 30 to remove loose cartilage in his right ankle, the Hawks announced Sunday.

Dunn has been sidelined with cartilage disruption in his right knee, but recently has been able to participate in modified workouts with the team. Although his knee was improving, as his on-court workload increased, Dunn started to experience discomfort in his right ankle and lower back.

According to the team, “a recent MRI revealed loose cartilage inhibiting his range of motion in the ankle and creating compensations in his knees and low back,” and the team opted for surgery at the Hospital of Special Surgery. Per the Hawks, his recovery timeline is unclear.

The Hawks acquired Dunn in free agency and were hoping his defensive prowess would give them a boost this season.