His club, Paris Saint-Germain, made the announcement that a wait-and-see approach would be taken, although it means Neymar will miss both legs of the Champions League round of 16 with Manchester United.
Neymar, 26, left the field in tears after suffering the injury to the same fifth metatarsal, although in a different spot, on which he had surgery last year, in PSG's 2-0 French Cup victory last week over Strasbourg.
"Paris Saint-Germain gathered together a group of world-renowned medical experts at the Ooredoo Training Centre to carry out a thorough review of the injury to Neymar Jr's right foot," it said in a statement.
"After detailed analysis by the specialists, a consensus was reached of a conservative treatment of Neymar Jr.'s injury to the fifth right metatarsal."
Neymar, the French club said, "is expected to return to the field within 10 weeks."
The club added: "Paris St-Germain sends its strongest support and encouragement to Neymar Jr to overcome this injury, with the courage and determination that the player has always shown."
Surgery most likely would end his second season with PSG and jeopardise his availability for Copa America this summer. It will almost certainly end his second season in Paris prematurely and seriously threaten his participation with Brazil.
PSG face Manchester United at Old Trafford on February 12 and in Paris on March 6.