Rory McIlroy
Rory McIlroy could end up missing both defences of his 2014 majorsGetty

Rory McIlroy remains a doubt for the PGA Championship after withdrawing from next week's WGC-Bridgestone Invitational. McIlroy, 26, missed the opportunity to defend his Open Championship at St Andrews in June after suffering a ruptured ankle ligament while playing football with friends.

Despite the innocuous circumstances behind the injury, it has been suggested that McIlroy could miss months of action, robbing him of the chance to defend his USPGA title at Whistling Straights in August. The final major of the year takes place a week after the Bridgestone Invitational.

"Unfortunately, I will not be defending my World Golf Championships-Bridgestone Invitational title," McIlroy said in a statement from tournament organisers on 30 July. "Best of luck to all the competitors and I look forward to returning to Firestone in 2016."

Last year the Northern Irishman won his fourth career major and his second in succession to solidify his status as the best golfer on the planet with a one-stroke lead at Valhalla.