The Serbian has been reluctant to publicly disclose his vaccination status and expressed hope that vaccines would not become mandated at events. They did at the Australian Open which complicated things for Djokovic who refused to speak on the matter even after the news became known. It's not yet known whether he will travel to Australia and play at the events with the ATP Cup starting a few days.
Only when Djokovic officially touches down in Australia and if he does, will we know whether he will play? The organizers don't know, the fans don't know, only Djokovic knows and he won't tell it publicly. For Emilio Sanchez, it's a clear sign. The former doubles no. 1 and Spanish Davis Cup captain wrote on Twitter:
“For everyone with the hope that he goes to AO. He will withdraw also from AO. For me, there is not one chance"
After backlash from fans he clarified his stance by writing:
“I was just telling my opinion, I don’t know him, I don’t have a crystal ball, but doesn’t look good for him to play. I admire him, his career, and his professionalism. My question is, how many times he played AO without any match before? Hopefully, I’m wrong and he’ll play.”