play one for a low probability grand slam, potentially get injured, and miss out on the Wimbledon (has to be a favourite to win it this year), and US Open? He’s not stupid. He is already the GOAT, adding a 2018 grand slam has marginal benefits. He would rather win Wimbledon and/or US Open at this stage.
with regards to your earlier comment. I tried to watch the earlier rounds of the last 4 opens. As a casual tennis enthusiast, the game isn’t particularly fun to watch outside the top 3-4. Everyone has incomplete games to them and the points aren’t exciting, they tend to run patterns on each other and it’s a grind/attrition. There is zero magic and most players tend to try to max out power and serve stats because thats whats needed to get near the top - finesse, vision, game sense is cast to wayside. Players with vision, accuracy, and shot making abilities like Federer’s are once in a generation - tennis will be a boring once he’s gone. I would not get up at 3am to watch Novak, Nadal, Murray, Cilic, Raonic (or anyone in the top 50 for that matter - http://www.atpworldtour.com/en/rankings/singles)
I’ve seen Federer play 3-4 times live. I agree that the top guys like him have a different aura than the rank 10-50 sorts, or even better than that. However, I don’t perceive enough game diversify from the same players to feel that the game is evolving or is different from year to year. Maybe this is because I don’t play tennis myself and cannot appreciate the more nuanced aspects of the game. There also seems to be a lack of occasion, since you can usually count on the top players doing well in tournaments. My point of view is influenced by personality and perhaps limited understanding of the sport, but I think it is not completely irrational.