Patrick Reed has revealed he has been in hospital with pneumonia.
The 31-year-old has not played since the WGC-FedEx St Jude Invitational after withdrawing from The Northern Trust with an ankle injury.
Given this latest news about his health, "Captain America" appears a doubt for next month's Ryder Cup – being outside the automatic qualifiers.
He said in a statement on the PGA Tour website: "The good news is, my ankle is OK. The bad news is I've been in the hospital with bilateral pneumonia.
"I'm on the road to recovery. Once I'm cleared from the doctors I look forward to returning. I wish you all the best and I can't wait to get back out there!
"Thank you so much for your support, it means a lot to me. Also, a special thank you to the doctors, nurses and staff at The Methodist Hospital in the Texas Medical Center."
Reed is currently ninth in the Ryder Cup standings and will not earn enough points to lift himself into the top six and qualify.
The American, who has played a key role at the biennial showpiece in recent years, could still be one of Steve Stricker's six captain's picks, although Reed faces stiff competition from the likes of Webb Simpson, Jordan Spieth, Patrick Cantlay, Harris English, Tony Finau and Daniel Berger.