London's Olympic Stadium will remain closed until at least August 2015, the authority responsible for its future said, adding there was no NFL bid to make it a permanent American football team base.
Dennis Hone, chief executive of the London Legacy Development Corporation, said a 2014 reopening of the venue in Stratford, east London, was "completely out," and that the earliest date "would be August 2015".
The stadium is scheduled to stage the 2017 World Athletics Championships.
London 2012 chief Sebastian Coe, elected chairman of the British Olympic Association on Wednesday and a vice-president of the International Association of Athletics Federations (IAAF), which runs the World Athletics Championships, said he would be keeping a close eye on developments.
"I am also the client with my position in the IAAF so we will be watching that very closely," Coe said.
NFL has brought annual regular season matches to northwest London's Wembley Stadium since 2007 and will stage two such games at the 90,000-capacity venue next year.
That prompted speculation that the NFL might look to make the 80,000-seater Olympic Stadium a permanent home for an American football franchise as the sport seeks to expand its appeal beyond the United States.
But Hone confirmed there were just four bids on the table to take on a 99-year lease at the Olympic Stadium, the centrepiece of the London 2012 Games, with NFL not among them.
"We have no formal bids outside of the competition or otherwise by American football to go in to the stadium," he told the London Assembly local authority.
"We are running a competition and we have four bidders. There are no bids outside that."
He did not rule out the prospect that a stadium built to include an athletics track in legacy could also work with the winter sport of American football. The combination would be "a challenge definitely," he noted.
The four bidders vying for the Olympic Stadium lease are nearby football clubs West Ham and Leyton Orient, the University College of Football Business and a firm wanting to stage a Formula One race that would go inside the stadium.
No date has been set for when a new tenant will be announced for the £486 million ($775 million, 610 million euros) stadium. A decision is not expected before December.
Hone said the amount of work needed to fine-tune the bids meant August 2015 or even August 2016 would be the most likely reopening date.