The Football Association is unable to confirm whether the new Wembley Stadium will be finished in time to host next year's FA Cup final on 13 May.
Barwick has booked Cardiff's Millennium Stadium just in case
"If Multiplex (the constructor) are true to their word we have every chance of staging the Cup final at Wembley," said FA chief executive Brian Barwick.
"Equally, we have taken the prudent step to book the Millennium Stadium."
The builders are due to hand over the stadium in March in order for test events to take place before the final.
Barwick added: "We are taking rain checks every couple of days. "We have been taking advice from experts and they still think it is on course to finish on time."