The Argentine striker was reported to have slipped during an excursion to Capri, an island off Italy's southern coast, and hit his face on the deck, injuring his jaw.
He was treated in a hospital on the island and discharged. Napoli, who visit Chievo in their next match on Saturday, did not immediately comment on the incident.
Higuain, who joined Napoli from Real Madrid in July after spending 6-1/2 seasons with the Spanish side, made his official debut in the 3-0 win over Bologna, when he had a goal disallowed for offside.
Higuain will miss Argentina's World Cup qualifier away to Paraguay on Sept. 10 while he completes a two-match suspension.