Kylian Mbappé was taken to hospital urgently.
Real Madrid's 26-year-old world star had been affected by an inflammation of the stomach and intestines.
A few hours later, the Frenchman was discharged.
"Kylian Mbappé was discharged from the hospital in the afternoon and has returned to Real Madrid's training camp. Mbappé will continue to receive specific medical treatment and gradually return to team play", it says in a statement from the club.
Real Madrid is in the USA to play in the World Championship. When the team started the tournament against Al-Hilal in Miami, Kylian Mbappé was outside the squad.