He is looking to regain fitness for the US Open
Rory McIlroy has withdrawn from the final golf tournament before the US Open because of injury.
The World Number 2 pulled out of this week's BMW PGA Championship at Wentworth with the same rib problem.
He suffered from a stress fracture to his ribs earlier this year.
Wentworth looks mint this week. Gutted not to be there, but well done to everyone involved getting the course back to where it should be!— Rory McIlroy (@McIlroyRory) May 26, 2017
His agent says he is not playing in next week's Memorial Tournament in an effort to be fit for the US Open.
"All focus is on getting back to full health for the US Open," he said.
The 2017 US Open is closing in with the second major of the year beginning on June 16th.
The Memorial Tournament takes place two weeks beforehand.