One of the greatest tennis players of all time believes Grand Slam matches in the men's singles should be reduced to three sets.
The 18-time Grand Slam singles winner Martina Navratilova says this would help to reduce the increasing number of injuries suffered by many of the top players.
The 56-year-old, a winner of nine Wimbledon titles, thinks the physical demand on male players in the modern game is not good for their health.
Many five-set matches are now lasting in excess of five hours and in recent years Rafael Nadal has been plagued by knee injuries, while Andy Murray missed the recent French Open with a back problem.
Navratilova told Laureus.com: "It's really becoming so taxing that I believe one day we will have two out of three sets in the Grand Slams, otherwise they're going to be taking people out on stretchers.
"We have always had issues with injuries but this year it came to light more so when the top guys are hurt.
"Rafael Nadal's had issues, he was out for about eight months. Now Andy Murray has missed the French Open because of a bad back and Novak Djokovic had issues as well with his ankle.
"They put a lot more hours in and everybody hits the ball harder, and you have to run harder. Plus the courts are slower so the rallies take longer. This has to take its toll on the body.
"You play a long match and it takes you months to recover, because it's like running a marathon in sprints, but then sometimes you have to go out and play a match the next day or two days later.
"I think a way to curb it would be to play the Grand Slams for men only two out of three sets."