Rory McIlroy has insisted that his record when playing with Jordan Spieth will not play a part during the first two rounds of the US PGA Championship.

The world's top two golfers play together at a tournament for the fifth time in their career today and tomorrow, and McIlroy has scored lower in five of the seven rounds they have shared.

However, McIlroy was keen to stress that those rounds were before Spieth's rise so far in 2015, where he won the first two Majors before just missing out on three in a row at last month's Open Championship.

"We're all going to have bad days and it just so happened that Jordan had a couple of off days whenever we were playing together," McIlroy told reporters.

"But I really don't think you can look too much into the head-to-head when guys are playing together, especially in the first two rounds.

"Okay, maybe if it was a final round and we were in contention to win you can maybe look into it a bit more, but first two rounds, I wouldn't put too much importance on that."

McIlroy is the current world number one, but due to his recent absence because of ankle ligament damage and Spieth's Major wins, he will be overtaken if the young American wins this weekend.