The largest crowd at any UK sports event this weekend will watch the St Louis Rams play the New England Patriots at Wembley this evening, the sixth National Football League regular-season game to be played here. But American Football has ambitions for London beyond a single annual showpiece, with two Wembley games already on the calendar for next season.
And with a number of NFL officials talking of an eventual London franchise, perhaps even more significant is the announcement that the Jacksonville Jaguars will play a "home" game at Wembley in each of the next four seasons. Is this a team who struggle to sell out their stadium testing the water for a permanent move from north-east Florida to north-west London? Don't print the London Jaguars T-shirts just yet, says Alistair Kirkwood, the managing director of NFL UK.
"I can understand the logic, but it needs to be seen as more basic than that," he explains. "First we had to prove that London games could work for players and fans. Going to two games is another step. Jacksonville coming for four games tests the theory that a returning team is something that fans will latch on to.
"Rather than having an impact on the Jaguars' future, it's more that we're doing something else that hasn't been done before so we can get new insights. It allows us to plan over a longer term and build more of a presence rather than a team just coming over in October and then disappearing."
The alternative to relocating a team is creating an expansion franchise – a completely new club with a roster put together from free agents, college graduates and players from existing teams – but expansion teams can take a decade to become competitive.
Whether London gains by relocation or expansion, it will still leave those American cities without NFL franchises, such as San Antonio and Los Angeles, asking: "Why them before us?"
What has seldom been questioned is that London would be the logical location for the first step outside the US. "The language does help, and this is a much bigger sports market than anywhere else in Europe, with a greater consumption of multiple sports, not just the top three or four," Kirkwood says. "It's a territory a lot of NFL people know, and the fact that we did so well in the 1980s proves that it can become big in this market again. It's not as if we were trying to grow cricket in the United States, where you couldn't point to anything done in the past."
Steven Jackson, the Rams star running back, agrees. "To grow, the NFL has to go outside the States, and London has the ability to support a successful franchise," he says. "Now it is just the technicalities, the logistics, the scheduling, immigration. And you'd have to pay tax here, you'd need a work visa. But it would make some players grow up – the appreciation of another culture and the way the world is."
So, when? "There isn't a time-scale," Kirkwood says. "You could not introduce a franchise until you knew you were completely sustainable and would fit in with what was happening within the US and the League as a whole. But if I had said in 2006 that we would play six regular-season games at Wembley, move to two games a year by 2013, and have a team commit to four visits, that would have sounded fanciful."
The NFL in London
1983 Minnesota 28 St Louis 10
1986 Chicago 17 Dallas 6
1987 LA Rams 28 Denver 27
1988 Miami 27 San Francisco 21
1989 Philadelphia 17 Cleveland 13
1990 New Orleans 17 LA Raiders 10
1991 Buffalo 17 Philadelphia 13
1992 San Francisco 17 Washington 15
1993 Dallas 13 Detroit 13
2007 NY Giants 13 Miami 10
2008 San Diego 32 New Orleans 37
2009 New England 35 Tampa 7
2010 Denver 16 San Francisco 24
2011 Chicago 24 Tampa 18
2012 New England v St Louis 2013 (29 Sept) Pittsburgh v Minnesota; (27 Oct) San Francisco v Jacksonville
London has had a professional American football team before. In 1991, the London Monarchs were the first champions of the 12-team World League of American Football, staged in North America and Europe with players assigned and paid by the NFL. The Monarchs played in front of 40,000 crowds at Wembley, where they beat Barcelona Dragons 21-0 in the first World Bowl. But, after the league suspended operations for two seasons before returning in 1995 as a six-team European league, the London crowds dwindled. The team moved to White Hart Lane, Stamford Bridge and then a series of smaller venues as the England Monarchs in 1998, their final year. Their best-known graduate was quarterback Brad Johnson, who led Tampa Bay to victory in Super Bowl XXXVII.