American Steve Stricker has pulled out of the BMW Championship midway through the tournament because of a sore neck.
"Steve has been battling some neck pain the past few days and the discomfort became more severe today," Stricker's representative, Jon Heaton, said.
"After consulting with his doctor, he has decided to rest at home for a few days in hopes of regaining full strength for the Tour Championship next week."
Stricker currently lies eighth in the FedExCup standings, with the final event of the lucrative play-offs still to come in Atlanta.
Only the top 30 after Sunday's final round at Cog Hill will progress to the Tour Championship, where a $10m (£6.3m) prize will be awarded to the overall points winner.
Englishman Justin Rose currently shares the lead with Marc Wilson after two rounds of the BMW.
