ORLANDO, Fla. (AP) _ Top doubles player Leander Paes is being treated for a brain lesion and will miss the U.S. Open, a hospital said Tuesday.

Paes, who's 30, has won three Grand Slam men's doubles titles and teamed with Martina Navratilova to win two major mixed doubles titles this year.

After having severe headaches for three days, Paes checked himself into a hospital near his Orlando home Sunday, and a scan showed that he has a brain lesion, M.D. Anderson Cancer Center spokeswoman Michelle Lynch said.

Paes was transferred to Anderson, in Orlando, on Tuesday, according to Lynch. Tests were being conducted to determine the lesion's cause, with the results expected within a few days, Lynch said.

She said he was alert and speaking.

Paes pulled out of the doubles competition at this week's tournament on Long Island, but U.S. Open and ATP Tour spokesmen said they didn't know about Paes' condition.

Paes teamed with Navratilova last month to win the mixed doubles title at Wimbledon, her record-tying 20th championship at the All England Club. Paes and Navratilova also won the mixed doubles title at the Australian Open in January. Paes also won the 1999 mixed doubles at Wimbledon and was a bronze medalist in tennis at the 1996 Atlanta Olympics.

Paes has won 27 men's doubles titles, including the French Open in 1999 and 2001, and Wimbledon in 1999.

He was No. 1 in the ATP Tour's doubles rankings in 1999.