Manchester United hope to build a 100,000-capacity stadium within the next six years, a source told ESPN.
The club hopes to make a final decision on whether to build a new stadium or refurbish Old Trafford before the end of the year.
The project is estimated to cost more than £2 billion (US$2.6 billion) and United hope to build a stadium with a capacity of between 90,000 and 100,000 by 2030.
Co-owner Sir Jim Ratcliffe has previously said he would prefer to build a new stadium on the site of the existing stadium, possibly using land behind the Stretford End.
Plans are yet to be finalised, but club officials have drawn inspiration from a number of similar projects around the world, but most notably SoFi Stadium and the surrounding regeneration project near Los Angeles.
United played Arsenal at SoFi Stadium in Inglewood on Saturday as part of their pre-season tour of the United States and sources told ESPN that club chiefs have visited Los Angeles several times in recent years.
Former United striker Andy Cole, who was part of the contingent in Los Angeles for the game against Arsenal, said: “Manchester United fans and everyone in the north of England deserve a truly world-class stadium, and SoFi has set the standard to aspire to.
“I don't make this comparison lightly, but there are parallels to be seen with the opportunity at home in Manchester. A new or redeveloped stadium at Old Trafford could be the focal point for the revitalisation of the surrounding area.”
Sources have told ESPN that United chiefs have also visited the refurbished Bernabeu in Madrid and spent time at Wembley and Tottenham Hotspur Stadium, as well as following the Chicago Bears' Burnham Park project.
Ratcliffe has made the stadium project a priority since becoming part-owner in February.
In March, it was announced that a joint working group had been set up, including Manchester Mayor Andy Burnham and former United captain Gary Neville, to explore options.
Speaking at a fans' forum earlier this month, chief operating officer Collette Roche said: “The working group is making good progress in exploring the possibilities of a new or redeveloped stadium that would be the focus of wider regeneration.”
Roche also promised that fans would be consulted before any decision was made on the possible sale of naming rights for the new venue, but admitted that “all options” would need to be considered to fund the project. The working group will look at all funding options, including a public-private partnership.
