More than 400,000 (423,004) seats have been left empty during the opening round of Club World Cup group matches in the United States.
Stadiums have been 56.8% full, with more than half a million (556,369) spectators attending.
Nine stadiums have been used for the first 16 matches of the tournament, with a combined capacity of 979,373.
The expanded tournament is being treated as a dress rehearsal for the international men’s World Cup next summer, which will be held in the USA, Canada and Mexico.
Of the 16 matches played so far, half of the matches have seen attendances below 50% of the capacity of the stadium.
The lowest attended game was South Africa’s Mamelodi Sundowns win over South Korean side Ulsan HD in front of 3,412 spectators at Inter & Co Stadium in Florida.
The fixture between Ulsan HD and Mamelodi Sundowns was by far the worst attended match.
The official attendance meant the stadium was just 13.6% full.
Local journalist Maher Mezahi claimed to have counted 97 fans before kick-off and 577 with 10 minutes left to play.
The stadium for River Plate’s win over Japanese club Urawa Red Diamonds was 17% full, while it was 20% for Salzburg’s win over Pachuca in Cincinnati.
Only 31% of the capacity of Atlanta’s Mercedes-Benz Stadium saw Chelsea beat LAFC in their opening match.
Despite the setbacks, Fifa is optimistic that attendances will increase. In a statement on Tuesday, it said that “four of the five top-selling group stage matches are still to come”.
