Djokovic needs no reminding that he's closer to the end of his career than the start and that injury is the biggest enemy facing any professional athlete. However, the competitor has bounced back from a number of previous knocks, and if anyone can secure that feat of 25 Grand Slams, no one is better qualified.
The oldest player to win a Grand Slam title was Ken Rosewall, who won the 1972 Australian Open at the age of 37 years, one month, and 24 days. Djokovic is already beyond that mark, and the chances of him adding one more slam to his belt at this stage look rather uncertain.