Rory McIlroy has taken to social media to confirm that he has ruptured his ankle ligaments.
The world number one suffered the injury while playing football with friends on Saturday.
It remains unclear how long the 26-year-old will be out of action for, but the four-time major winner is expected to be sidelined for a lengthy spell.
The Open Championship at St Andrews gets underway in less than two weeks.
A photo posted by Rory McIlroy (@rorymcilroy) on
McIlroy has won four titles on both the PGA and European Tour so far this year.