He is currently not allowed to travel to the U.S. due to not being vaccinated against COVID-19, while Australia issued a three-year banning order after he was deported back in January. That means he's unlikely to play another Slam until France next year, on his least favorite surface. Aged 35, judging by his competitors, Djokovic still has a handful of years at the top ahead of him, but the opportunities to rack up the Slams are slowly ebbing away from him.