Belfast, July 6 (IANS): World No.1 golfer Rory McIlroy on Monday said he has ruptured a ligament in his left ankle playing football and is a huge doubt for 114th The Open starting on July 16 at the St Andrews in Scotland.

The Northern Irishman, who won the 2014 The Open, revealed the news on his Instagram account, alongside a picture of him on crutches and his left foot in a protective boot.

"Total rupture of left ATFL (ankle ligament) and associated joint capsule damage in a soccer kickabout with friends on Saturday," 2011 US Open champion McIlroy wrote.

Four-time Major winner McIlroy, 26, however, didn't rule himself out of the field for the third Major of the year.

"Continuing to asses extent of injury and treatment plan day by day. Rehab already started... Working hard to get back as soon as I can," McIlroy, who won the 2012 and 2014 PGA Championship, added.

McIlroy, 11-time winner on the PGA Tour of the US, was set to play in the Scottish Open this week in preparation for the Open.

At this year's Masters Tournament and US Open, Mcilroy finished fourth and tied ninth, respectively. World No.2 Jordan Spieth of the US clinched both the titles and is hot favourite to win The Open.