Billie Jean King says men should not play five sets at Grand Slams
Former world number one Billie Jean King has called for an end to five-set matches for men at Grand Slams.
King, who won 12 Grand Slam titles including six at Wimbledon, said men's matches could last too long.
The 74-year-old suggested women were willing to play five sets too but people wanted "quality over quantity".
"You do not get paid in the entertainment business by how long you play for," said King at the launch of the WTA Finals in Singapore.
Longer matches and a packed schedule have been cited as a possible cause of the rise in serious injuries among some of the game's stars with Andy Murray, Rafael Nadal, Novak Djokovic and Stan Wawrinka all suffering serious injuries in the past 12 months.
"Everyone keeps saying women don't want to play five sets but I don't want the men playing five sets anymore - it takes too much out them," said King, who founded the Women's Tennis Association in 1973.
Since 2007, men and women have been paid the same prize money at Grand Slams - the only events, along with the Davis Cup, where men's matches are best of five sets throughout - but women are paid significantly less at women-only events compared with similar-sized men's events.
Djokovic, the president of the ATP player council, has previously called for men to earn more than women, saying more people watch men's tennis.