DUBAI, United Arab Emirates -- Rory McIlroy said the fatigue he's felt for the past several weeks may be the lingering effects of dengue fever.
The No. 2-ranked McIlroy had two late bogeys Friday to finish with a 1-under 71 and 7 under at the Dubai World Championship. McIlroy is five shots behind Alvaro Quiros of Spain.
He must win to have any chance of claiming the European money title ahead of Luke Donald.
McIlroy said he got blood test results back Thursday that showed his white blood cell count remained low. He said all he can do is "keep hydrated" to help offset the fatigue.
"To be honest, I don't feel too bad," he said after his round Friday. "But yeah, we got the blood test results back last night. It was basically the same. Platelet count was low and my blood cell count was low as well."
The U.S. Open champion believes he picked up a "mild case of dengue fever" when he was playing tournaments in South Korea or China at the end of October and early November. Dengue fever is spread by mosquitoes, generally in tropical areas, and can cause fever, rash and joint pain.
McIlroy also didn't rule out that it could've been a case of food poisoning. He said he didn't have it anymore and was just suffering the "the lasting effects which my body is trying to fight to obviously get back to 100 percent."
McIlroy said he would see a doctor Saturday before determining if he will pull out of the Thailand Golf Championship that starts next week.
He said the only way for him to fully recover was get plenty of rest, cut down on the travel and "let my body just get back to full health as quickly as possible."