Rory McIlroy hoping to end season on a high

Rory McIlroy has conceded that his recent troubles have prevented him from reaching his pre-season targets.

The 23-year-old managed to reach the top of the world rankings at the beginning of the year but a difficult summer in Europe and on the PGA Tour means that there are still achievements he wants to experience this season.

"There were a few goals I set myself at the start of the year, which I achieved - getting to number one in the world and winning a tournament early," McIlroy told reporters ahead of the USPGA Championship. "The second half has still been pretty good, but a little bit more of a struggle.

"If I had to give my season a grade to this point I'd probably give it a B, but there's still a lot of golf left to play."

The Northern Irishman's season will improve dramatically if he can win the second major tournament of his career at Kiawah Island this week.