The 20-year-old, who was booed by Verde-Amarela fans during the unconvincing win, has suggested that people are expecting too much from him.
"I felt sick because of what happened against South Africa. I am not a machine," he told Globo Esporte.
"I was exhausted after Friday's match, both physically and mentally. I just want to keep on playing and help Santos and the national team."
Neymar has been capped 21 times at senior international level, scoring nine goals.