The NFL has taken a resolutely step-by-step approach to gauging the practicality of transplanting a team to Britain since playing the first regular-season game here in 2007, and is likely to continue to proceed with caution.
Arthur Blank, the owner of the Atlanta Falcons, said last week that more and more of his fellow owners "are now fully on board and supportive."
But he also described a London team only as "a possibility, six or seven years away".
"People who don't know the NFL don't know what putting a franchise in a city really means," Alistair Kirkwood, the managing director of NFL UK told The Independent.
"League average attendance is 66-67,000. And you should only put a team where you think it is going to work, to be absolutely viable. Otherwise you run the risk of diluting the success they've enjoyed."
Only one of the 10 Wembley games so far has attracted a crowd under 81,000, but they have usually featured at least one big-name team.
The low-profile Jacksonville Jaguars, owned by Fulham owner Shahid Khan, are playing a game in London every year for four years, notionally to see if a team can build support although many believe that they could be the team to cross the pond for good.
So far, they have been paired with crowd-pulling opposition, such as the Dallas Cowboys in two weeks.
The acid test will be selling Jacksonville versus Buffalo.There is also more to it than simply moving one team.
Each NFL team plays in a four-team division, which would mean committing three other teams to an annual London visit.
The next step is expected to be staging games at Wembley on successive Sundays to see how the pitch, criticised last Sunday, holds up, and to ask teams playing in London to dispense with the traditional week off - not a concession the NFL could find room for in its schedule if a London team becomes a reality.
"There is no value to anybody putting a team here and finding the rigours of the season do not allow it to compete at the highest level," Mark Waller, the NFL executive vice-president, said.
"So that's the work we are going to do. That's probably a five-year piece of work."
However, the report all but ruled out a London Super Bowl on the grounds of kick-off time, additional costs and a potentially adverse reaction from the US core market.