Real Madrid forward Kylian Mbappe has been hospitalized with an acute case of gastroenteritis, the Spanish club said Thursday. World Cup winner Mbappe missed Madrid's opening game at the Club World Cup against Saudi Arabian team Al Hilal in Miami on Wednesday because of a fever.Coach Xabi Alonso said he hoped the France international would be available for the team's next game against Pachuca on Sunday. But his hospitalization casts doubt over what part he might be able to play in the monthlong tournament in the United States. Madrid said Mbappe would undergo a series of tests and follow the appropriate course of treatment. Mbappe's absence is a blow to the tournament, which FIFA president Gianni Infantino hopes will be one of the elite events in soccer and rival competitions like the Champions League and Premier League in popularity and value.After Lionel Messi, Mbappe is arguably the biggest star in the show, with Madrid one of the favorites to lift the trophy in the inaugural edition of the tournament.But a crowd of more than 62,000 at Hard Rock Stadium missed out on a rare chance to see him in person in the U.S. when he was unavailable for Madrid's surprise 1-1 draw by Al Hilal on Wednesday.Gastroenteritis is also known as stomach flu and symptoms can include vomiting and diarrhea.Mbappe's hospitalization comes almost exactly one year after he sustained a broken nose at the European Championship and had to wear a face mask to continue playing in the tournament.FAQsQ1. What is current club of Kylian Mbappe?A1. Kylian Mbappe plays for Real Madrid.Q2. Who is Kylian Mbappe?A2. After Lionel Messi, Kylian Mbappe is arguably the biggest star in the show, with Madrid one of the favorites to lift the trophy in the inaugural edition of the tournament.