"I haven't communicated with him since he arrived in Belgrade. It is clear that it hit him mentally, it will hurt him for a long time and it will be difficult to get it out of his head.
"I can't imagine how he handled it. It must have been a huge suffering."
French parliament recently approved a vaccine pass law which would require people to have a vaccination certificate in order to enter places such as restaurants, cafes, cinemas and long-distance trains.
This would apply to tennis players wanting to compete in the French Open — putting Djokovic in an awkward spot if he wants to play in the next grand slam of the year in Paris.
But Vajda said he can't understand why such a discussion is taking place months out from the next major, which is scheduled to start in May.
"I don't understand … why it's important for them to announce this now about the tournaments that will take place in May, when the world doesn't even know what will happen to the pandemic in a month," he said.
"I do not want to underestimate the whole situation. It is serious in the world. But what is the purpose of discussing it now in January? Is it still about sport?"
Despite all he's endured in recent weeks, Vajda said Djokovic "is strong, resolute and has not yet said his last word in tennis".
Vajda's comments are the most explosive to come out of the Djokovic camp since his last legal challenge failed and he was deported.
The nine-time Australian Open champion released a measured statement last weekend in response to the decision to kick him out of Australia.
""I will now be taking some time to rest and to recuperate, before making any further comments beyond this," Djokovic said.
"I am extremely disappointed with the ruling to dismiss my application for judicial review of the decision to cancel my visa, which means I cannot stay in Australia and participate in the Australian Open. I respect the Court's ruling and I'll co-operate with the relevant authorities in relation to my departure from Aus.
"I am uncomfortable that the focus of the past weeks has been on me and I hope that we can all now focus on the game and tournament I love. I would like to wish the players, tournament officials, staff, volunteers and fans all the best for the tournament.
"Finally, I would like to thank my family, friends, team, supporters, fans and my fellow Serbians for your continued support. You have all been a great source of strength to me."
