DUBAI - World number two Rory McIlroy is exhausted and run down and may have to pull out of next week's inaugural Thailand Golf Championship, his Horizon Sports management team said on Friday.

Rory McIlroy of Northern Ireland is seen on the 18th hole during the Dubai World Championship at the Jumeirah Golf Estates in Dubai, Dec 8, 2011. [Photo/Agencies]

"Rory has a low white blood cell count and low platelets," a member of Horizon Sports who declined to be identified told Reuters at the Dubai World Championship.

"He has a doctor coming to see him again on Saturday evening and they have just told him to hydrate, take iron and salt tablets and rest.

"We've told the Thailand organisers, they know he's been sick for a few weeks. He wants to play there but I think he'll make a decision tomorrow night," added the source.

"The doctors are saying it's exhaustion, him being run down. The blood count obviously affects his energy levels in a big way."

U.S. Open champion McIlroy, who is locked in a straight fight with Luke Donald to win the money-list at the European Tour's season-ending event in Dubai, has had a gruelling playing schedule in recent weeks.

That, however, did not stop the 22-year-old Northern Irishman finishing his first round in spectacular fashion on Thursday, blitzing his way to five birdies in the last six holes to close within two strokes of leader Peter Hanson of Sweden.