Jim Furyk has been forced to pull out of the BMW Championship after picking up a wrist injury.
Despite being just one-over-par after six holes, Furyk walked off the course after the issue made it difficult for him to continue but he is confident of recovering in time for next week's Tour Championship and the Presidents Cup.
"I'm very concerned," the 45-year-old told reporters. "I would like to be ready for both of them, and if I can't get ready for next week, I would like to get ready for the Presidents Cup.
"But also I want to play with a chance to compete, and right now being out here I have no chance to compete this week with the pain I was feeling and with what I had shot-wise."
Jason Day was 10-under through 17 holes before rain halted the leader's progress on day one in Illinois.
