Crane joins PGA casualties
American Ben Crane has become the latest player to withdraw from the US PGA Championship due to back issues.
The 38-year-old pulled out before the start of the second round at Valhalla after carding a three-over-par 74 in the opening round.
The world No 104, who won his first title since 2011 at the St Jude Classic in Memphis nine weeks ago, becomes the fourth US player to quit the event.
Former winner David Toms withdrew on Tuesday and world No 6 Matt Kuchar pulled out with back issues before Thursday's first round.
Defending champion Jason Dufner also called it a day after 10 holes of the opening round as he continued to suffer with a neck problem that has troubled him since the Masters.
Dufner was eight over at the time after running up a triple-bogey eight at the 10th.