Italian Antonio Matarrese, Fifa vice-president and a member of its organising committee for the 2002 World Cup, said: "If other candidate cities have a great stadium like Yokohama, I believe it will be a big headache for the Japanese organising committee."
The 2002 event is being co-hosted by Japan and South Korea, with the opening match to be staged in South Korea and the final in Japan.
Yokohama, which has the largest stadium in Japan with a capacity of 70,000, has already declared its candidature to stage the final. Saitama also wants to host the game and Tokyo is expected to challenge as well.
Matarrese said Fifa would wait for a recommendation from the Japanese organising committee before submitting a report to its board of directors.
There had been rumours that the decision to allow Japan and South Korea to host the tournament jointly might be reversed, but Matarrese denied any such idea.
"This is not the time to talk about Fifa's decision because it's in the past," he said, clearly exasperated. "We must move forward because the world is watching what happens at the World Cup in 2002."Reuse content