Rory McIlroy is looking to become the first player to win the Masters and US PGA in the same year since Jack Nicklaus in 1975

Rory McIlroy abandoned a practice round after only three holes, abruptly halting his preparations for the US PGA Championship which starts on Thursday at Aronimink near Philadelphia.

The Masters champion, bidding for back to back major wins, was suffering discomfort in his right foot hours after revealing that he had removed the nail on his little toe earlier this week.

"Softened it up in the shower and just ripped it off," the Masters champion laughed before removing his sock to show off the results of his surgical handiwork to a handful of reporters shortly after his pre tournament news conference.

McIlroy had planned to play nine holes of practice on Tuesday afternoon, having made an earlier scouting trip to the Donald Ross designed course in Pennsylvania.