Manchester United want to make Old Trafford bigger than Wembley.
The Sun says Red Devils chiefs will push capacity up to 95,000 from the current 75,000.
That would make United's stadium the biggest in the country.
The plans will please manager Alex Ferguson, who has pressed the case for expansion to the Glazer family, who own United.
He is determined to make watching the club more affordable and entice a fresh generation of fans.
The scheme is tied in with United's property holdings around Old Trafford.
George Johnstone, United's group property manager, said: "There is a strategic plan for the stadium."