More than 400,000 seats were 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 spectators attending.

Nine stadiums have been used for the first 16 matches of the tournament, with a combined capacity of 979,373.

The total attendance at matches has been 556,369, with 423,004 empty seats.

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.

Journalist Maher Mezahi claimed to have counted 97 fans before kick-off and 577 with 10 minutes to kick off.

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".Fifa says nearly 1.5m tickets have been sold for the tournament and despite the issues there have still been some large attendances.

The highest-recorded crowd of 80,619 watched Paris St-Germain's 4-0 win over Atletico Madrid at the Rose Bowl Stadium in California.

The three matches in Miami, which has a large Hispanic and Latino population, have been highly attended. Fifa said the opening game between Inter Miami and Al-Ahly was watched by 60,927.

Boca Juniors' Group C match against Benfica had more than 55,000 in the 65,000-capacity Hard Rock Stadium.

The third game in Miami had 62,415 attend Real Madrid's 1-1 draw with Saudi Arabian side Al-Hilal.

Inter Miami and Boca Juniors are playing in Miami again later in the group stage.

Fifa scheduling headache

There were gates of 18,161 for Juventus' win over Al-Ain and 21,152 for Bayern Munich's 10-0 win over Auckland City.

The stadiums were 91% and 81% full, respectively - with the games taking place in smaller stadiums.

Fifa may come to rue not doing the same with some of the matches scheduled during regular work hours.

On Monday at 3pm local time, Chelsea beat LAFC in front of 22,137 fans - but in a stadium which can hold 71,000 spectators.

Doug Roberson of the Atlanta Journal-Constitution thinks there were several factors, but "it's not because people here don't care about soccer".

"The people aren't here because it's Monday at 3pm," he said. "Frankly I am surprised there are as many as there are."Chelsea played at the stadium in Atlanta two years ago and almost sold out, with more than 70,000 fans watching them face Newcastle in a friendly tournament named the Premier League Summer Series. That match took place at 8.15pm.

Two or three games are being played during regular work hours on every other weekday until the group stage ends on 26 June (noon, 2pm and 3pm local time).

Tuesday's noon kick-off in New York saw more than 40,000 empty seats at the Met Life Stadium for the goalless draw between Borussia Dortmund and Fluminense.

There were 30,000 empty seats in the same time slot on Wednesday in Philadelphia as Manchester City opened their campaign against Moroccan club Wydad Casablanca at the Lincoln Financial Field.The Club World Cup has had to go up against the Concacaf Gold Cup, which is also being held in the United States and Canada.

The continental football tournament is contested between 16 nations across North America, Central America and the Caribbean.

This year Saudi Arabia have also been invited to take part.

Attendances have also been down for the tournament - the United States beat Trinidad and Tobago 5-0 in front 12,610 fans at the 18,000-capacity Pay Pal Park in California.

Two years ago the same fixture in the same tournament attracted 40,000 fans in North Carolina. (BBC Sports)

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