Ian Poulter is expected to miss the next four months of the season due to a foot injury, effectively ending his chances of qualifying automatically for the Ryder Cup.
Poulter is currently 42nd on the European Points list, but could still feature at Hazeltine as one of European captain Darren Clarke's five vice-captains.
Clarke appointed Thomas Bjorn, Paul Lawrie and Padraig Harrington last week, with Poulter, Lee Westwood and Jose Maria Olazabal understood to be in contention for the remaining places.
"I am obviously disappointed to be in this situation, especially during a Ryder Cup year," Poulter said in a statement. "Right now, rest and rehab take priority in me returning to full strength later this season. I look forward to resuming a full schedule as soon as I am able."
Poulter's doctor, Ara Suppiah, added: " Ian has been hampered by an arthritic joint in his right foot for the best part of two and a half years.
"The condition has progressed rapidly over the last year warranting numerous cortisone shots (within therapeutic limits) to allow him to play. Unfortunately, he continues to be in pain whilst walking and practicing.
"Further cortisone shots run the real risk of thinning the bones (osteopenia) and stress fractures, which might require treatment in a cast and significant time away from the game.
"We feel that the best option at this stage is to take some time off to allow complete recovery and rehabilitation (including customised orthotics and modification of footwear) of his foot. This will give him the best chance of returning to the game sooner and preventing further deterioration of the affected joint."