World number one Rory McIlroy has withdrawn from the Honda Classic in Florida.

The defending champion was struggling badly during his second round at Palm Beach - dropping 7 shots during his opening eight holes - including a disastrous treble-bogey 7 on his 6th hole.

The final straw for McIlroy was when he found the water on his 9th hole and he walked off the course without even completing the hole. He walked straight to his car and then left the golf course at PGA National.

As yet, there is no indication if he is struggling from injury or illness.

In contrast, Graeme McDowell is one-under for his 2nd round, which has seen him climb to 4 under for the tournament - three shots off the lead.

Image: McIlroy at last week's WGC match play event