St. Louis, USA: European Ryder Cup captain Thomas Bjorn withdrew Wednesday from the 100th PGA Championship because of a back injury, tournament officials announced.
"Unfortunately having to WD from @PGAChampionship due to reoccurrence of my old back not holding up!!" the 47-year-old Dane tweeted.
"Thank you to @PGA for having me this week and good luck everyone playing this week. Looking forward to watching it all unfold!"
Bjorn will be paying special attention as he must fill out his roster for next month's Ryder Cup showdown against the United States at Le Golf National in France.
European players have another three weeks before qualifying eight players on points and world rankings, leaving him four more selections.
Bjorn, who matched his best major showing with a share of second at the 2005 PGA, was replaced in the field by American Kevin Streelman.
Spain's Rafa Cabrera Bello and American James Hahn will tee off alongside Streelman at 7:23 a.m. (1223 GMT) in Thursday's opening round at Bellerive Country Club.