The Olympic Stadium will not reopen until August 2015 at the earliest, it was revealed today.
Football is still among the front runners to be a tenant at the showpiece venue but a 2014 reopening is "completely out, it would be August 2015" at the earliest, said Dennis Hone chief executive of the London Legacy Development Corporation (LLDC).
There are four bids on the table about the future use of the venue and an American Football team is not among them. West Ham are among the bidders.
He told the London Assembly's budget and performance committee the amount of work needed to fine tune the bids would make August 2015 or even August 2016 the most likely reopening date.
Money spent so far in the process has looked at the design options.
Talks have been held with the bidders but none of the adaptation work has been taken to the market yet.
Hone said: "We have no formal bids outside of the competition or otherwise by American Football to go in to the stadium.
"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.
Whichever bid wins, the venue could have multiple uses and the stadium will host the World Athletics Championships in 2017.
A venue with a capacity of around 50,000 seats might be needed for those championships, Hone predicted.
No date has been set for when a new tenant will be announced and a decision is not expected before December.