XM Sirius PGA Tour Radio is reporting Rory McIlroy's driver was deemed to be nonconforming at the PGA Championship.

Rory McIlroy had to switch drivers at the PGA Championship after his gamer was deemed non-conforming, according to a report by PGA Tour SiriusXM Radio’s Jason Sobel. McIlroy is known as the best driver of the golf ball of his generation.

McIlroy’s driver was reportedly ruled non-conforming on Tuesday at the PGA Championship, and three days later McIlroy had hit just 10 fairways through 36 holes.