Wimbledon marathon man John Isner has urged locker-room rivals to ignore any niggling pain and give fans value for money after a rash of first-round retirements.
Isner spent 11 hours and five minutes on court when beating Nicolas Mahut at Wimbledon in 2010, being barely able to stand after the longest match in history, and the American says only players in agony should quit contests at grand slam level.
Seven men abandoned singles matches over the first two days of this year's championships, including Australia's Nick Kyrgios, but they still pocketed STG35,000 ($A59,000) each for their efforts as first-round losers.
And while the circumstances of those withdrawals were different, Isner believes Centre Court spectators were left short-changed after the matches on Tuesday featuring Novak Djokovic and Roger Federer were cut short.
Djokovic was leading Martin Klizan 6-3 2-0 when the Slovakian succumbed to a calf injury, before Alexandr Dolgopolov pulled the plug in his match at 6-3 3-0 down to Federer.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
Ticket prices on Tuesday for Centre Court were a minimum STG56 ($A95) and Isner said: "I know the Wimbledon Centre Court didn't get their money's worth today. That's for sure."
The 32-year-old would not want a seriously injured player to carry on, but he suggested those with knocks should make every effort to complete their matches.
Isner said: "If it's just excruciating pain, okay, you can't play. If something is tweaked here or there and you feel like you can give it a decent go without hurting yourself, I think they should stay out there and I think you owe it to the fans."
Federer and Djokovic called for Wimbledon to change its rules.
Federer said: "I felt like there was a bit of a let down from the crowd. They couldn't believe that it happened again, exactly the same situation."
The pull-outs highlighted the step-up in prize money at the grand slams. Wimbledon first-round losers pocket more than double the STG14,500 offered five years ago.
For players with pre-existing injuries, the temptation might become too great to take to the court.
The ATP, which is the body that runs the men's tour but not the grand slams, introduced a rule this year whereby a player with an injury can pull out but still receive first-round prize money.
A lucky loser then takes their place and competes for prize money from the second round onwards.
Federer said: "A player should not go on court if he knows he should not finish."
Djokovic said: "I support that kind of rule. It's really odd that Roger's result and my result more or less was the same."
