Graeme McDowell has conceded that the rest of the field can only hope they remain in touch with Rory McIlroy in the latter stages of the USPGA Championship.

McIlroy is the favourite heading into the final Major of the year following victories in the Open Championship and Bridgestone Invitational, and McDowell believes that his fellow Northern Irishman could once again prove too strong for his rivals at Valhalla.

"He's the best player in the world, currently," the 2010 US Open champion told reporters. "You can't set out trying to beat him this week, you can only hope to go down the stretch on Sunday afternoon, and hopefully I can be there and give it a shot."

McIlroy's victory in Ohio on Sunday saw him take the world number one ranking away from Adam Scott.