Glenn Robinson III is expected to be out three to four months after undergoing successful ankle surgery, the Indiana Pacers announced Friday.

Robinson underwent surgery to repair the medial and lateral ligaments in his left ankle, suffered on Sept. 29 in a scrimmage during practice. He had missed most of training camp and the preseason because of the ankle injury.

Robinson's loss is a blow to the Pacers, who considered him a key part of the franchise's rebuild in the post-Paul George era.