The 19-year-old Brazilian sustained an 80 per cent tear of his biceps femoris muscle during Chelsea's 1-0 defeat to Manchester United at Stamford Bridge in April, a diagnosis so severe that both the club's medical department and owner Todd Boehly pushed for an operation.
Estevao declined. The results of a second MRI scan taken two weeks ago vindicated that decision in striking terms.
"The Chelsea doctors wanted me to have surgery and even the Chelsea owner said he wanted me to have surgery. Two weeks ago, I had a second MRI scan, and the doctor asked if I was in pain or feeling anything.
"I said: 'No, doctor, I'm fine, I think I could even play already.' He said: 'Yeah, it really shows.' He showed me the exam image and said he couldn't see any more of the injury.
"He said he doesn't know what happened, because in the timeframe we're in, it shouldn't be that well-structured like it is."
Despite the remarkable physical recovery, the injury came too late in the season to change his World Cup fate. Brazil head coach Carlo Ancelotti did not include Estevao in his squad for the tournament in Canada, Mexico and the United States.
Neymar was selected among Brazil's forwards, though the veteran's participation in the early matches is in doubt after he suffered a calf injury of his own.
Estevao ended his debut Premier League season with eight goals and three assists across all competitions. Chelsea finished outside the top six and missed European football entirely. Their FA Cup campaign ended in a final defeat to Manchester City.