Matt Kuchar has withdrawn from the US PGA Championship due to a back injury.
The 36-year-old, who notified officials of his decision moments before he was due to tee off at Valhalla Golf Club, will be replaced by John Huh.
Kuchar was seen as one of the favourites to win the tournament following on from his 12th-place finish at the WGC-Bridgestone Invitational last week.
Replacement Huh was initially on standby to step in if Tiger Woods withdrew, but the American overcame a back injury of his own in time to compete.
