Vijay Singh, the 1998 and 2004 PGA Championship winner, withdrew on Tuesday because of a back injury.
Singh, 56, splits time between the PGA Tour and PGA Tour Champions and finished tied for 43rd on the senior circuit’s Regions Tradition last week. Singh failed to make the cut at the Masters last month at Augusta, finishing with a 12-over-par 156 in his two rounds.
Singh finished 78th in last year's PGA Championship at Bellerive Golf Course in St. Louis.
His place in this week's PGA Championship will be taken by J.T. Poston, who is 68th on the PGA Tour FedEx Cup points list.