The Minnesota Vikings and Pittsburgh Steelers are both 0-3 heading into Sunday's game at Wembley Stadium, and a fourth loss will all but put the playoffs out of reach for one of them.
The first of two regular-season NFL games is expected to be a sellout despite the teams' current woes.
"It doesn't bother me. I love the atmosphere," said Rachel Green, who with husband Matt has been to all six of the NFL games played at Wembley. "I prefer it to be close, which it will more likely be with them both 0-3."
As of Tuesday, about 84,000 tickets had been sold, with only singles and premium seats still up for grabs.
The Vikings arrived in London on Tuesday and were already mixing with local schoolchildren and fans as part of the duties of the designated home team. The Steelers arrive Friday.
All eyes will be on Peterson, the Vikings running back, and Roethlisberger, the Steelers quarterback, as they look to lead their clubs to victory with their seasons teetering on the brink. Minnesota lost 31-27 to the Cleveland Browns on Sunday, while the Steelers fell 40-23 to the Chicago Bears.
"These are two teams that the U.K. crowd have not seen before and you have star power with the Vikings in Adrian Peterson and, with the Steelers, you have one of the most successful franchises in NFL history," NFL UK managing director Alistair Kirkwood said. "What you want is a very competitive game, and you know you are going to get it with both teams going after a must-win."
The New England Patriots, New Orleans Saints and Denver Broncos are among the teams that have played in London since the International Series was launched. The New York Giants' victory over the Miami Dolphins in the inaugural 2007 game helped turn their season around en route to winning the Super Bowl.
The Vikings went 10-6 last season and made the playoffs, while the Steelers finished 8-8. When they were selected to play in London, no one could have expected they would be a combined 0-6 heading into this week's game.
"For me, the chance to see a team as storied and famous as the Steelers is a big draw," said 30-year-old Matt Green, who counts the Green Bay Packers as his favourite team. "It'll be interesting to see how a franchise that has been challenging year in, year out will cope with the difficulties they've been facing recently.
"To be honest, I would go regardless of the teams playing. The chance to hang out and chat with so many like-minded NFL fans is one of my favourite parts of the day."
The second game, scheduled for Oct. 27, also features two teams currently struggling. The Jacksonville Jaguars' 0-3 start is not a big surprise, but the reigning NFC champion San Francisco 49ers are unexpectedly 1-2 after two straight losses. Still, the 49ers will likely be heavy favourites.
That game is sold out, which bodes well for building the Jaguars' fan base in Britain. Jacksonville has signed up to play one of its home games at Wembley over the next three seasons. London, meanwhile, keeps being talked about as a potential home for a full-time NFL franchise in the future.
"You're going to get a very interesting story no matter what team plays," Kirkwood said. "We'll be able to track the Jaguars and see how they grow going forward."
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