Brooks Koepka has withdrawn from the CJ Cup due to a knee injury.

Reigning champion Koepka, who last won at the WGC-FedEx St Jude Invitational in July, was even par through his first two rounds at Nine Bridges, located on Jeju Island in South Korea.

Prior to the 2019-20 season the four-time major winner had stem cell-treatment to repair a partially torn patella tendon in his left knee.

He missed the cut at the Shriners Hospital for Children Open two weeks ago – his first tournament since returning.

It is unclear how serious Koepka's injury is or when he will be back on the course.

Justin Thomas went into round three of the CJ Cup at the top of the leaderboard and with a two-shot lead.