I see Fed is hoping to come back to play singles again. He's a few years ahead of Novak in age so this will be a portent of what Novak may face.
For Fed: As long as he can move past the injury I can see some flashes of his old self, but it will be hard to keep it up. Recovery at this age is the problem especially if you're in a tournament for a couple weeks and have matches day after day. I would actually like to see him and many other top singles players shift to doubles play to extend their careers and also popularize that aspect of tennis again. He could also take some trophies with the right partner that would add to the tally. That is how they are counting it still right, slam title wins, not broken down by singles and doubles.
As for Novak, I think he has years left on the singles court and I hope that when that time comes when he finds trouble getting to the finals of big tournaments. I'd like to see Novak play doubles at the end of his career as well to prove that in every category that he can rule the court.
