"It is cruel sometimes", Federer said of Cilic's physical difficulties.
With his knee fixed and body rested after sitting out the French Open, Federer is yet to drop a set at this year's tournament.
"I want to thank the physios here, Alejandro and Graham and Dr Phil. They helped". I had some tough ones in the finals, losing two against Novak (Djokovic).
True to form, Federer barely felt an ounce of pressure during the final.
Such is the man's greatness that he has been able to turn the clock back at an age when most players hang up their rackets. "It's a big deal, I love this tournament".
This is the first grand slam since Wimbledon 2003 at which four men ranked outside the top four have made up the semi-final line-up but Federer is playing as well as anyone in the world at the moment. The 2014 U.S. Open champion said it wasn't that bad on Friday, but it got more serious that night.
Sam Querrey became the first male American to reach a Grand Slam semi-final since Andy Roddick in 2002.
Williams is 37 and would be the oldest woman to win the Wimbledon title since Charlotte Cooper Sterry in 1908.
"It was actually very difficult to focus on the match, as well, as my mind was all the time blocked with the pain. So I just have to check the situation, if it's worth it to run after it or not".
Federer admitted post-match that he will feel privileged to be back on Centre Court again on Sunday.
"And then the girls were there too and my wife was emotional". If he beats Cilic in straight sets, this Wimbledon will be his second time winning a Slam without dropping a set.