Sam Allardyce believes London's Olympic Stadium could become "a white elephant" if West Ham United do not get the go-ahead to move in as tenants.
Speaking before the centrepiece of the London 2012 Games hosted a spectacular closing ceremony on Sunday night, Allardyce warned that it could go "to wrack and ruin" without the regular use and big crowds that top flight football would provide.
The stadium's future has been a controversial subject, with the Hammers initially denied tenancy amid disputes with Tottenham, who unveiled their own plans to move there, and Leyton Orient.
Orient chairman Barry Hearn had voiced fears that his club could be driven out of business if West Ham moved to the stadium, which is very close to the League One outfit's Brisbane Road home.
The Hammers will find out next month whether their bid to lease the Olympic Stadium has been accepted, and Allardyce told The Times: "If they keep the stadium for athletics, the only time it will ever get a big crowd again after the Olympics is when they hold the World Championships there in five years.
"You only have to look around the world at some of the Olympic Stadiums that have been built. They're white elephants now - there are weeds growing there. Look at the Bird's Nest in Beijing. Look at Athens.
"The Olympic Park is a fantastic place, but it can't be left to rack and ruin. If a club with the history and fanbase and potential of West Ham don't go there, the concern would be that the park is left empty the vast majority of the time.
"I can understand some West Ham fans feeling that they don't want to leave the history and tradition of Upton Park, but it's an incredible opportunity for the club to move forward."
Last week, Allardyce said he believed a move to Stratford would turn West Ham into a major force in the English game.
Allardyce, who steered the club back to the Premier League via the play-offs last season, said: "Everyone who is a part of West Ham United knows how much it would benefit the club.
"It would take this club to another level if our bid is accepted. It would be a dream come true - and there is nothing I can say more certain than that."
Hammers officials believe the extra revenue the Olympic Stadium would generate on matchdays would allow the club to establish themselves and compete with the game's bigger spenders.