SHANGHAI (AP) Billy Horschel flew halfway around the world only to withdraw from the HSBC Champions with a sore back.
A PGA Tour official said the injury was not considered serious.
Horschel tweaked his back before leaving Florida for the final World Golf Championship of the year. The 2014 FedEx Cup champion gave it two days and tried to stretch it out on Tuesday before a practice round until deciding it was not worth risking hurting it more.
He was replaced in the 78-man field at Sheshan International by Cameron Smith of Australia.