Novak Djokovic is widely regarded as one of the strongest tennis players mentally. Some of the victories the Serb was able to complete over the years have been truly special but at the 2021 US Open, he showed that he is human after all. Tennis coach and the uncle of Rafael Nadal, Toni Nadal was a bit surprised to see it saying:
“The enormous weight of all that was at stake for him made it impossible for him to resist Daniil’s relentless level of play. And I have to admit, I was surprised to see him so affected. He may have been a little less resilient lately, but we all know his tremendous ability to withstand moments of maximum tension with strength and focus."
Cracks in Djokovic's armour showed at the Olympics as well where he collapsed against Alexander Zverev after smashing him in the opening set. Either way, Nadal isn't worried as he predicts Djokovic to recover very well from the defeat:
“Djokovic knew he was facing the most crucial match of his life, the meeting that was to determine the much-talked-about debate in tennis: who is the best player in the history of our sport. It is certain that this defeat will be painful for the Serbian but he will recover.”