The diagnosis directly impacts the coaching staff's plans for the coming days. The number 10 will miss the matches against Panama, this Sunday (31st), and against Egypt, on June 6th.
The recovery period may also rule the player out of Brazil's World Cup opener against Morocco.
His participation will depend on how well he progresses physically in the coming weeks. "It's not just swelling," said the Brazil team doctor.
The confirmation of the injury comes a day after Neymar missed the first official training session with the national team at Granja Comary, in Teresopolis, on Wednesday, when he was sent to a local clinic for tests.
The star had already arrived with swelling in his calf area. The problem began on May 17th, when the forward felt pain during Santos' 3-0 defeat to Coritiba in the Brazilian league.
Since then, he hadn't returned to training with the ball, raising a warning sign that was unfortunately confirmed by today's medical report.