Roger Federer and Novak Djokovic called for Wimbledon to change its rules after both of their opponents retired on a disgruntled Centre Court.
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 first-round match at 6-3 3-0 down to Federer.
Klizan and Dolgopolov were two of seven men to withdraw during their first-round matches, with Viktor Troicki and Janko Tipsarevic both spending less than 20 minutes on court.
Federer and Djokovic even joked about playing a practice set to appease the crowd on Centre.
Federer said: "I felt like there was a bit of a letdown from the crowd. They couldn't believe that it happened again, exactly the same situation.
"I feel for the crowd. They're there to watch good tennis. At least they see the two of us who gave it all they had.
"They saw other players that tried at least. They put in another match on Centre Court. It's unfortunate that it happened today like this."
It was a highly unusual situation but highlighted an unwanted side effect of the big increases in prize money for first-round losers at the grand slams.
Those exiting at the opening stage of this year's Wimbledon will pocket €35,000 - more than double the €14,500 offered five years ago.
For players with pre-existing injuries, the temptation to take to the court knowing victory, or even completing the match, is unlikely is all too great.
The ATP have introduced a rule this year whereby a player with an injury can pull out but still receive the 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. The question is, did they truly believe they were going to finish? If they did, I think it's okay.
"The ATP has adjusted its rule. But maybe the slams should have a look at what they could do for the players to make it just a little bit easier. It's a lot of money."
The grand slams and the WTA are monitoring the impact of the ATP rule but no formal talks about introducing it have taken place.
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.
"It doesn't happen often really. This tournament has a special place in players' careers. The aura of Wimbledon has probably always been the strongest of any tournament.
"I'm sure that most of the players on the tour, if not all, feel that. Especially if you walk out on the Centre Court, there is a responsibility. I'm sure they tried their best."
Dolgopolov has no doubt players do step on court knowing they will not complete a match - although he insisted that was not the case for him.
The Ukrainian, who suffered a right ankle injury three weeks ago, said: "The reality is you're going to have that, that's obvious.
"For most of the draw, it's significant money for the guys to pay their coaches and keep on playing.
"I've made enough money, I've had a long career, I've been top 20. If I know it's a risk for my body, I don't go there to just step on court.
"I practised yesterday, it was okay. I was comfortable, I had no problem going on court for sure. I was quite confident with the foot.
"Obviously it's a pity that I couldn't finish. I talked to the physio and asked what are my risks and he said he could not tell me so I had to decide myself."
Tipsarevic also insisted he was not playing just for the money, with hamstring pain that had come on suddenly three days ago flaring up again.
But he also does not believe players should be criticised for doing so given the huge expense and low prize money below the main tours.
He said: "You have a lot of players here who fought their way to be in the Wimbledon main draw by playing in Challengers.
"This year I made a huge jump mainly through Challengers and after half a year I am more or less at break even.
"So if a guy who all his life is playing Challengers suddenly has the chance to play in the Wimbledon main draw, where a first-round loss is £35,000, I don't think anybody has the right to judge him."
The Serbian lasted just 15 minutes against Jared Donaldson, winning five points in five games.
Elsewhere, last year's runner-up Milos Raonic began his campaign with a 7-6 (7/5) 6-2 7-6 (7/4) win over Jan-Lennard Struff while there were also wins for Dominic Thiem, Alexander Zverev, Grigor Dimitrov and Juan Martin del Potro, who could face Djokovic in round three.
Queen's champion Feliciano Lopez would have had high hopes here but was one of those forced to retire, trailing two sets to one to Adrian Mannarino.
John Isner believes players should feel an obligation to complete matches if possible.
The 23rd seed, who defeated fellow American Taylor Fritz, said: "You don't really know what the player is going through.
"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.
"I know the Wimbledon Centre Court didn't get their money's worth today. That's for sure."