Russia's Maria Sharapova has pulled out of the $1.5 million Dubai Tennis Championships citing a viral illness.

The Australian Open champion, who also won in Doha last week, is unbeaten in 2008 and had been scheduled to play her first match in Dubai on centre court in Tuesday's evening session.

"Unfortunately I have been battling a virus for several days and it's reached a point where I'm unable to compete," the world number five said in a statement on Tuesday.

"This is really disappointing to me, but I do intend to come back to Dubai next year and hopefully have a great tournament."