Mumbai, Sept. 4 -- Apart from the downside of having to miss his daughter's birthday, Novak Djokovic is exactly where he would have hoped to be coming into the season's last Grand Slam: in the last four, just like the first three Slams. Now is when things have become a lot more difficult for the 38-year-old this year. Carlos Alcaraz awaits in the US Open semi-final. It's the same stage where Djokovic has exited in this season's three Slams due to an ageing body (retired against Alexander Zverev at Australian Open) and younger challengers (lost to Jannik Sinner at French Open and Wimbledon). Now is when Djokovic desperately seeks an extra push to lift him against his current two biggest rivals that, at this stage of Slams, invariably lurk. A...