Murray, 31, is hoping his body will get him through to Wimbledon this summer where he can bow out of tennis at his home Grand Slam.
But realistically, the Australian Open, which commences next week, could be the final event which he forces his body to play through the pain.
The Scot gets his campaign underway on Monday against Roberto Bautista Agut, but he is still feeling the impact of hip surgery.
But during Murray’s pre-tournament press conference he broke down in tears when announcing he will retire this year.
The News quickly reached Federer and he was instantly taken aback.
“It hit me hard,” Federer told the Sunday Age.
“Of course, I’ve seen Andy struggling you know with his hip and with his fitness for quite some time now.
“You want somebody to go there and feel like he’s happy to retire.
“The problem is it’s not his decision, it’s the body’s decision and that naturally hurts.”
Murray performed admirably to win three Grand Slam titles while competing wth the likes of Federer, Rafael Nadal and Novak Djokovic.
But world No 3 Federer does not think Murray was unlucky to be competing in the same era.
“I mean, he won Wimbledon, he won the Olympics, became world No 1,” Federer added.
“Is that unlucky? I don’t know. I always said you can have great careers, you can have great careers side by side.
“Maybe from Aussie stand point, yes he’s been unlucky because he made five finals here [in Melbourne] and never won one.
“But that’s why I think he will also be even more loved you know because he maybe didn’t make it here.
“But I don’t think he will say or that we should say that he’s been unlucky, I think he’s worked extremely hard and when he got to world No 1 or he won all those big event that he did, totally deserved them.
“He put in the workload and he’s an extremely talented player as well.”
Source : EXPRESS