Golf:Ryder Cup hopeful Simon Dyson is out of this week's BMW PGA Championship — the European Tour's flagship event — as he tries to shake off a stressed hip injury. The reigning Irish and Dutch Open champion withdrew from the Players Championship in Florida two weeks ago after the first round.

Dyson, who finished third at Wentworth last year, is replaced in the field by Dutchman Maarten Lafeber.

Luke Donald tees off on Thursday knowing a successful defence of the title will take him back to world number one. Donald took top spot for the first time when he beat incumbent Lee Westwood in a play-off a year ago.

He stayed there until Rory McIlroy’s victory at the Honda Classic in Florida in early March, and there have been four further changes between the pair since. The 23-year-old from Holywood, who next month defends his US Open crown in San Francisco, is also in the field for the European Tour’s flagship event.

If Donald finishes second, McIlroy would have to win to keep hold of the number one position and if McIlroy misses the halfway cut — as he did on his last start at the Players Championship two weeks ago — Donald would need to finish eighth or better.

Westwood is currently third on the rankings, but just too far back to have a chance to leaping over the other two this week.