Honestly i think Fed don't even care about this as much as Nadal. He don't even try to compete like the past nowadays in their matches. Maybe he really think Nadal can't pass him in slams. No more exertion and he hand over the match when Nadal gets physical. Body is more impt to him i think. Unless its indoors and he knows he only need to exercise in short intervals for max 1 hour.
Their matches are not fun to watch anymore cuz Federer kept stopping the rallies(hit to net mostly) when he has a free shot. Its like pointless in his opinion that Nadal will retrieve and he will need to hit the same shot again.
So you are saying he is a weak kitten? We knew that before