American Bud Cauley is receiving treatment in hospital after being involved in a car accident in Ohio on Friday evening.
Cauley was a passenger in the car and is being treated for five broken ribs, a collapsed lung and a fractured lower left leg according to a statement from his management company IMG, which was released to Golf Channel.
The 28-year-old, who missed the cut at the Memorial Tournament following rounds of 77 and 76, was scheduled to play in Monday's US Open qualifier in Memphis, but has withdrawn.
World number one Justin Thomas wrote on Twitter: "Not many people I love more in this world than my guy BC. Was a rough nights sleep last night. Glad to see and hear he's been doing better. Prayers are needed and all we can do is hope for the best! Get well soon, homi."