World number one Brooks Koepka has withdrawn from the United States' Presidents Cup team because of injury and will be replaced by Rickie Fowler.
Koepka, 29, re-injured his left knee during October's CJ Cup in South Korea and will miss the event at Royal Melbourne from 12-15 December.
The Presidents Cup sees a US side compete against an international team, excluding European players.
"I regret not being able to compete. I need more time to heal," said Koepka.
"I'm sorry I won't be able to represent the red, white and blue and I wish my team-mates nothing but the best as they work to retain the Presidents Cup.