Four-time major champion Brooks Koepka faces a race against time to be fit for the Ryder Cup after being forced to withdraw injured from the Tour Championship.
Koepka, 31, was unable to complete of his third round at East Lake after appearing to injure his left wrist on the tenth hole.
The former world No.1 seemingly struck a buried tree root in the act of hitting a wedge shot, immediately letting go of the club and recoiling in pain. He tried to play on but walked in on the 13th.
Afterwards, Koepka tried to play down the significance of the injury, explaining that his withdrawal was purely precautionary.
However, US captain Steve Stricker will no doubt be concerned with this year's COVID-delayed Ryder Cup just over two weeks away.
Koepka was the fourth of six automatic qualifiers for the American team, with the remaining six wild cards set to be revealed by Stricker this coming Wednesday.
He will be hoping that he doesn't need to draft in any additional reinforcements to cover Koepka, who has endured an injury-ravaged couple of seasons.
In addition to issues with his left wrist which caused him to miss the 2018 Masters, he was also sidelined for parts of 2018 and 2019 with an injury to his left knee, an injury that resulted in his withdrawal from the 2019 Presidents Cup at Royal Melbourne.
Further ailments hijacked his 2020 season, with an injury to his right knee forcing him to sit out this year's Players Championship.
How serious this latest problem ends up being remains to be seen but he has also postponed a $250,000 charity match that he was scheduled to play this week against Barstool Sports founder Dave Portnoy.
Koepka has played on two US Ryder Cup teams to date, in 2016 and 2018, amassing a 4-3-1 record and winning four-and-a-half points from a possible eight.