Bellamy: Millennium Stadium too big for Wales
Bellamy told reporters before their Group Four match against Russia in the 74,000-capacity stadium: "With the crowds we are getting at the moment, a smaller stadium will definitely help us."
Wales, who have no realistic chance of reaching next year's World Cup finals in South Africa, had sold only 10,000 tickets by Tuesday and the Football Association of Wales International Committee will discuss the issue next week.
"If you're getting 18,000 in such a big stadium and there's such big gaps... it's hard to create a tempo from it because there isn't much atmosphere there," added the skipper.
In contrast, Northern Ireland manager Nigel Worthington, whose team will go top of Group Three if they beat Slovakia in Belfast on Wednesday, said playing at their small Windsor Park ground was one of the big factors in their recent revival on the international stage.
"We have 13,500 in and it is worth 80,000," he said.
"They are worth their weight in gold to us as always. They are our 12th man and we always have on-days at Windsor." he added.