Federer tops Forbes' list of top-earning tennis players

Roger Federer was the highest earning tennis player in the world over the last 12 months, making about $90.6 million before taxes, despite the Swiss maestro's time on court being limited by injury, Forbes' said on Thursday.

Federer, who has skipped this year's U.S. Open due to a knee injury, made less than $1 million from playing tennis, with the bulk of his income coming from endorsements, Forbes' said Japan's Naomi Osaka is the second-highest earner on the list, with $60.1 million in pre-tax income, more than 90% of which she made off court, with Serena Williams, Novak Djokovic and Rafa Nadal completing the top five.