Doctor Rodrigo Lasmar said Neymar left as a precaution after feeling soreness while jogging.
Brazil may have struggled in their World Cup opener but their failure to beat Switzerland has not left the players worrying about qualifying for the knockout phase just yet, midfielder Philippe Coutinho said on Tuesday.
"Neymar is going to be marvellous in Russian Federation and win the trophy for us", Carlos said.
Neymar recently returned to full fitness after suffering a fracture to his metatarsal and a sprained ankle during Paris St Germain's Ligue 1 match against Olympique de Marseille on February 25, so any fresh injury concern will be worrying.
"As soon as he felt the pain he went to the physio".
"Neymar injured??? No chance for Brazil to win now", one fan wrote.
Whether this limits his participation against Costa Rica remains to be seen.
World Cup Daily: Poland and Colombia fail to impress, while it just keeps getting better for hosts Russian Federation. "He is a very important player for us".
"We spoke about the possibilities and the ways to qualify and points".
"All games are hard", he said.
And former Barcelona star Rivaldo, who tasted World Cup glory in 2002 and scored 35 goals in 75 appearances for Brazil, believes anything less than victory is unacceptable. Earlier, the first major upset of the tournament took place when Mexico's frenetic counter-attacking football saw them stun defending champions Germany 1-0 at the Luzhniki Stadium.
Jack Wilshere announces he will leave Arsenal
It may worry you that much of our mainstream press is increasingly reporting with a strong right-wing bias. He was often hampered by injury, but made 125 Premier League appearances under Arsene Wenger.