India, Aug. 13 -- Monica Seles, nine-time grand slam champion and one of the greatest tennis players of all time, revealed that she was diagnosed with an autoimmune disease called myasthenia gravis. The former Serbian-American world number one explained that she has been struggling against this disease over the last five years, and decided to speak out about it in a bid for awareness.

In an interview with the Associated Press, Seles explained how the signs were slow to come at first, but slowly grew to a level where it could not be avoided.

"I would be playing [tennis] with some kids or family members, and I would miss a ball. I was like, 'Yeah, I see two balls.' These are obviously symptoms that you can't ignore," explained Seles.

The...