Injury keeps Casey out of PGA Championship

CHASKA, Minn., Aug. 13 (UPI) -- World No. 3 Paul Casey of England withdrew from the PGA Championship early Thursday because of a muscle strain that has bothered him for weeks.

Casey pulled out before he was to tee off at Hazeltine National Golf Club in Chaska, Minn.

Robert Karlsson and Trevor Immelman withdrew earlier because of injuries.

Casey, who has 10 wins on the European Tour and one in the United States, strained a rib muscle prior to the British Open in July. He played in the open but withdrew from his next tournament, the WGC-Bridgestone Invitational last week.

The Englishman trails only No. 1 Tiger Woods and Phil Mickelson in the world rankings.