Djokovic won the Australian Open, French Open and Wimbledon titles in 2021 but was unable to defend his Melbourne Park crown due to his refusal to get vaccinated against COVID-19.
The Serb was deported on the eve of the hardcourt major and his coach Ivanisevic said it had been a real setback for the entire team.
"It was a tough year, especially for him, but also for us that were close to him," Ivanisevic told reporters on Sunday. "People, after that they never come back to tennis or to anything.
"We all expected for him (to say) after a couple of weeks, 'okay, forget about Australia, let's go back and practice.' It did not happen like that. It took a long time ...
"Unbelievable how he recovered and how he got through that. It's really for me heroic because it was not easy to digest everything and come back to play tennis. People like him you don't doubt. He's a great champion."
Djokovic, who had lost both his two previous meetings with Kyrgios, had to show resilience of a different kind on Sunday, fighting back from a set down to win 4-6 6-3 6-4 7-6(3).
Ivanisevic heaped praise on Kyrgios, saying it was almost impossible to prepare for a match against a player as unpredictable as the Australian.
"Nick Kyrgios is a genius, tennis genius," the Croatian said. "Kyrgios, for me is the best server in the game by far. Unbelievable tennis player."
Ivanisevic also said he had to give Djokovic a quick refresher on the tournament's history after the Serbian said in his on-court interview that he was inspired to take up tennis after watching Pete Sampras win Wimbledon in 1992.
Sampras has actually lost to Ivanisevic in the semi-finals that year, with the Croat then defeated by Andre Agassi in the final.
"I said, 'Man, it was me in the 1992 final,'" Ivanisevic said. "Sampras was in the semi-final losing to me!"
