The 30-year-old missed his side's last two group games before making a scoring return from the penalty spot in their 4-1 last-16 thrashing of South Korea on Monday.
"I was afraid of not being able to play in this World Cup again but I had all the support of my friends and family and I tried to find strength where I could not find it," said Neymar.
"I did not feel any pain in my ankle. I think my performance went very well and I'm very content, but that said I think we can always improve and that's what I will try to do."
Brazil coach Tite denied suggestions that he may have shown a lack of respect to his team's opponents after joining Richarlison in a celebratory dance on the touchline during the first period.
Roy Keane was among those who slammed the celebration but Tite insisted it had been pre-planned and was not aimed at mocking the South Koreans.
"I said (to Richarlison) if you show it to me I'll do it, but we have to be careful because various people will say it was disrespectful," said Tite.
"I didn't want it to be misinterpreted as anything less than a sense of happiness for the goal and for the result, and not that we were disrespecting our opponent which was not the case."
South Korea coach Paulo Bento announced his departure from the role in the wake of his side's comprehensive defeat.
The 53-year-old, who took over in August 2018, said he had already made the decision to bow out after the tournament prior to travelling to Qatar.
Bento said: "We just have to think about the future and it will not be with the national team of South Korea.
"I have just announced to the players and to the president of the South Korean federation and this was a decision I had already taken since September that was set in stone.
"Today I have confirmed it and I have to thank them for everything they have done. They have given their very best and I have been very pleased and proud to have been their manager."