Rory McIlroy was one of roughly 50 players whose drivers were tested before the PGA Championship as part of a normal procedure aimed at monitoring club limits.

Rory McIlroy hasn't had his best stuff so far at the PGA Championship, but he still has an outside chance to make a run after making the cut on the number. The Masters champion struggled to hit fairways during his first two rounds before the news broke that he is using a backup driver this week at Quail Hollow.

It emerged on Friday that the driver McIlroy had planned to use had failed tests conducted by the United States Golf Association on Tuesday.