Wimbledon champion Serena Williams says a return to tennis is driving her recovery from a blood clot on the lung.
The 29-year-old added that emergency surgery for the pulmonary embolism was the "scariest moment in my life".
Williams said she had several more blood clots on her lungs and is injected herself twice a day with blood-thinning medication.
The American believes she may be able to make a return in a few months as she waits for the remaining clots to dissolve.
Before her latest health scare she been sidelined by a cut to her foot suffered celebrating her Wimbledon win - her 13th Grand Slam title - outside a Munich restaurant.
In her absence from competition, Williams has slipped to 11th in the world with Denmark's Caroline Wozniacki taking her place at the top of the rankings.
