The world number one - who received backlash after hosting the event during a pandemic - tested positive for the disease, alongside his wife, fitness coach and fellow players Grigor Dimitrov, Borna Coric and Viktor Troicki.
Players were seen not adhering to social distancing measures, with several pictures showing them embracing each other and playing basketball prior to the tournament's cancellation.
Djokovic released a statement saying he was "extremely sorry", but Manchester United midfielder Matic insists Serbia's restrictions had reduced further than those of other countries, stating distancing measures were not legally required.
"People need to understand that the situation in Serbia was better than here [in England]," Matic told Sky Sports.
"The country allowed everyone to do whatever they want, everything was open, the shopping centres and the restaurants.
"So they started to live normal lives because our country was closed for three months completely. You were not allowed to walk on the street, you couldn't leave your home, so it was different [than England]."
"When they opened they said, 'you are more than free to do whatever you want'," he added. "Before that tournament, there was a game with 20,000 people and nobody said anything about that.
"I just wanted to say that it is not his fault that he made the tournament, he just wanted to help the players play competitions. I don't see that he (did) something wrong."
Additional reporting from Reuters.