Published: Dec 09, 2011 4:38 PM EST
Updated: Dec 10, 2011 7:30 AM EST

DUBAI, United Arab Emirates (AP) - Rory McIlroy says the fatigue he has 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 that showed that his "platelet count was low and white blood cell count (was) low."

He said he would see the doctor Saturday before determining if he will pull out of the Thailand Golf Championship that starts next week.