The Fulham manager had initially denied interest in the post left vacant by Glenn Hoddle, but he said he would talk to the FA if Mohamed al Fayed, who owns his west London club, gave permission.
Yesterday the Division Two leaders were knocked out of the FA Cup by Manchester United.
Keegan said the growing speculation that he would succeed Hoddle was a big compliment. But he was sad that discussion of the England job had overshadowed Fulham's performance in its biggest match in three years.
"Today gave me a real boost so on one side you've got that emotion," he said.
"On the other side, you have that pull every Englishman should have if he's going to be a manager and your country comes along. Maybe you should jump at it and forget everything."
Keegan made his name as a player with Liverpool, then captained England. After years out of football, he returned amid a blaze of publicity to manage Newcastle United.
Other names are still in the running. Tony Adams, the Arsenal captain, backed Terry Venables to return as the England coach.
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