Federer, who skipped the French Open this year to give his body time to recover from his incredible exploits in the first half of the season which he began by winning an 18th major at the Australian Open, said he hoped Murray would not live to regret battling through the pain barrier.
Effervescent Roger Federer moved serenely into the Wimbledon semi-finals a few weeks before his 36th birthday and then expressed his concern for two stricken rivals on Wednesday.
Before the Swiss enjoyed a majestic 6-4, 6-2, 7-6(4) defeat of Canada's Milos Raonic on Centre Court, defending champion Andy Murray hobbled to a five-set defeat by American Sam Querrey -- his nagging hip injury finally getting the better of him.
Later Novak Djokovic, the man who beat Federer in the 2014 and 2015 finals and was his prospective semi-final opponent this year, quit with an elbow injury against Czech Tomas Berdych.
Federer, who skipped the French Open this year to give his body time to recover from his incredible exploits in the first half of the season which he began by winning an 18th major at the Australian Open, said he hoped Murray would not live to regret battling through the pain barrier.
"You wish them well right away as a rival to them and a friend," Federer, who is now favourite to claim a record eighth Wimbledon title, five years after his last one, said.
"You want them to be healthy again. Andy, I hope by playing he didn't make things worse. It's big for him to step out on court and give it a go, even though maybe knowing, like me last year, the chances are slim he was going to defend this title.
"I have a lot of respect for him doing that. I just hope that he comes out on the other side now not having to miss much later on. I just hope he can recover quickly and get ready for America really, or Canada for that matter."
Federer said he had learned to manage his body -- citing last year's French Open when he arrived at Roland Garros struggling with knee and back injuries and decided to pull out of the tournament before it began.
It ended a run of 65 consecutive grand slam appearances.
"I was doing fitness with my fitness coach and after like 10 minutes, I looked at him and said, I don't know what we're doing in Paris seriously. My knee is swollen. I don't feel ready to go. My back is funny. My knee is not well. What are we doing?
"As a team, we just decided that it's best to skip it. So it wasn't should I or shouldn't I? The body didn't really allow me to play, in my opinion. I got a little sad, I must admit, because I felt like it was a great record for me to keep going.
"But health is so much more important than trying to hang onto some sort of a record."
Murray and Djokovic have both turned 30 and while these days that no longer signals a downturn, Federer had some sage advice.
"Once you hit 30, you've got to look back and think: How much tennis have I played? How much rest did I give my body over the years? How much training have I done? Did I do enough? Did I overdo it or not enough?" he said.
"Sometimes maybe the body and the mind do need a rest."
Of his own physical condition there is no doubt, though.
"I'm playing very well. I'm rested. I'm fresh. I'm confident too. Then great things do happen."
