Actors in costume stand in front of a backdrop depicting the Minnesota Vikings' logo before the NFL International Series game at Wembley Stadium in London on September 29, 2013. (Dave Shopland/NFL)

Recording artist Gene Simmons poses for a photograph before the NFL International Series game between the Pittsburgh Steelers and the Minnesota Vikings at Wembley Stadium in London on September 29, 2013. (Sean Ryan/NFL)

Minnesota Vikings quarterback Matt Cassel (16) is sacked by the Pittsburgh Steelers in the NFL International Series game at Wembley Stadium in London on September 29, 2013. (Sean Ryan/NFL)

Minnesota Vikings wide receiver Jerome Simpson (81) gestures for a first down against the Pittsburgh Steelers in the NFL International Series game at Wembley Stadium in London on September 29, 2013. (Sean Ryan/NFL)

Minnesota Vikings defensive end Jared Allen (69) goes up against Pittsburgh Steelers tight end Heath Miller (83) in the NFL International Series game at Wembley Stadium in London on September 29, 2013. (Sean Ryan/NFL)

Minnesota Vikings wide receiver Cordarrelle Patterson (84) makes a catch against the Pittsburgh Steelers in the NFL International Series game at Wembley Stadium in London on September 29, 2013. (Sean Ryan/NFL)

Pittsburgh Steelers quarterback Ben Roethlisberger (7) hands off to Pittsburgh Steelers running back Le'Veon Bell (26) while facing off against the Minnesota Vikings in the NFL International Series game at Wembley Stadium in London on September 29, 2013. (Sean Ryan/NFL)

Pittsburgh Steelers quarterback Ben Roethlisberger (7) passes against Minnesota Vikings defensive end Jared Allen (69) in the NFL International Series game at Wembley Stadium in London on September 29, 2013. (Sean Ryan/NFL)

Pittsburgh Steelers quarterback Ben Roethlisberger (7) is brought down by Minnesota Vikings outside linebacker Chad Greenway (52) during the NFL International Series game at Wembley Stadium in London on September 29, 2013. (Sean Ryan/NFL)

Minnesota Vikings running back Adrian Peterson (28) high-steps his way into the end zone against the Pittsburgh Steelers in the NFL International Series game at Wembley Stadium in London on September 29, 2013. (Sean Ryan/NFL)

Minnesota Vikings running back Adrian Peterson (28) celebrates a touchdown against the Pittsburgh Steelers in the NFL International Series game at Wembley Stadium in London on September 29, 2013. (Sean Ryan/NFL)

Pittsburgh Steelers quarterback Ben Roethlisberger (7) is sacked on the last play of the game by Everson Griffen (97) and Chad Greenway (52) of the Minnesota Vikings in the NFL International Series at Wembley Stadium in London on September 29, 2013. (Sean Ryan/NFL)

Minnesota Vikings wide receiver Greg Jennings (15) runs with the ball ahead of Pittsburgh Steelers cornerback Ike Taylor (24) in the NFL International Series at Wembley Stadium in London on September 29, 2013.. (Sean Ryan/NFL)

Pittsburgh Steelers quarterback Ben Roethlisberger (7) evades a sack from Minnesota Vikings linebacker Erin Henderson in the NFL International Series at Wembley Stadium in London on September 29, 2013.. (Sean Ryan/NFL)

Pittsburgh Steelers cornerback Ike Taylor (24) and Minnesota Vikings wide receiver Cordarrelle Patterson (84) reach for a pass in the NFL International Series at Wembley Stadium in London on September 29, 2013.. (Sean Ryan/NFL)

A Minnesota Vikings fan cheers on his team against the Pittsburgh Steelers in the NFL International Series at Wembley Stadium in London on September 29, 2013. (Sean Ryan/NFL)

Adrian Peterson RB Minnesota Vikings runs with the football against the Pittsburgh Steelers in the NFL International Series at Wembley Stadium in London on September 29, 2013. (Sean Ryan/NFL)

Minnesota Vikings defensive end Jared Allen (69) celebrates a sack against the Pittsburgh Steelers in the NFL International Series at Wembley Stadium in London on September 29, 2013. (Sean Ryan/NFL)

The line of scrimmage is shown during the 2013 NFL International series game between the Pittsburgh Steelers and the Minnesota Vikings at Wembley Stadium in London on September 29, 2013. (Dave Shopland/NFL)

NFL fans cheer during the 2013 NFL International series game between the Pittsburgh Steelers and the Minnesota Vikings at Wembley Stadium in London on September 29, 2013. (Dave Shopland/NFL)

The line of scrimmage is shown during the 2013 NFL International series game between the Pittsburgh Steelers and the Minnesota Vikings at Wembley Stadium in London on September 29, 2013. (Dave Shopland/NFL)

NFL fans cheer during the 2013 NFL International series game between the Pittsburgh Steelers and the Minnesota Vikings at Wembley Stadium in London on September 29, 2013. (Dave Shopland/NFL)

Pittsburgh Steelers running back Le'Veon Bell flips over as he scores a touchdown during the NFL football game against Minnesota Vikings at Wembley Stadium, London, Sunday, Sept. 29, 2013. (AP Photo/Sang Tan)

Pittsburgh Steelers running back Le'Veon Bell dives to score a touchdown during the NFL football game against Minnesota Vikings at Wembley Stadium, London, Sunday, Sept. 29, 2013. (AP Photo/Sang Tan)

A marching band performs on Regent street during the NFL street block party on September 28, 2013. (Dave Shopland/NFL)

NFL fans participate in football activities on regent street during the NFL street block party on September 28, 2013. (Dave Shopland/NFL)

Fans take photos during the NFL Regents Street Block Party in London on Saturday, September 28, 2013. (Sean Ryan/NFL)

NFL fans pose for photographs on regent street during the NFL street block party on September 28, 2013. (Dave Shopland/NFL)

NFL fans line regent street during the NFL street block party on September 28, 2013. (Dave Shopland/NFL)

NFL fans line regent street during the NFL street block party on September 28, 2013. (Dave Shopland/NFL)

Children participate in an NFL Play 60 event during the Regents Street Block Party in London on September 28, 2013. (Sean Ryan/NFL)

Fans take photos during the NFL Regents Street Block Party in London on Saturday, September 28, 2013. (Sean Ryan/NFL)

Pittsburgh Steelers fans pose for photographs during the NFL Regents Street Block Party in London on Saturday, September 28, 2013. (Sean Ryan/NFL)

Minnesota Vikings cheerleaders pose for a photograph with Swedish model Caroline Winberg, and recording artist Gene Simmons, who will be performing the American National Anthem before the International series game between the Pittsburgh Steelers and the Minnesota Vikings on Sunday, September 29, 2013. (Dave Shopland/NFL)

Minnesota Vikings cheerleaders pose for a photograph with Swedish model Caroline Winberg, and recording artist Gene Simmons, who will be performing the American National Anthem before the International series game between the Pittsburgh Steelers and the Minnesota Vikings on Sunday, September 29, 2013. (Dave Shopland/NFL)

The Minnesota Vikings cheerleaders perform on stage in London on September 27, 2013. (Dave Shopland/NFL)

The Minnesota Vikings cheerleaders perform on stage in London on September 27, 2013. (Dave Shopland/NFL)

The Minnesota Vikings cheerleaders perform on stage in London on September 27, 2013. (Dave Shopland/NFL)

The Minnesota Vikings cheerleaders perform on stage in London on September 27, 2013. (Dave Shopland/NFL)

The Minnesota Vikings cheerleaders perform on stage in London on September 27, 2013. (Dave Shopland/NFL)

The Minnesota Vikings cheerleaders perform on stage in London on September 27, 2013. (Dave Shopland/NFL)

The Minnesota Vikings cheerleaders pose for a photograph in London on September 27, 2013. (Dave Shopland/NFL)0ap2000000251491

Minnesota Vikings cheerleaders at the top of the Shard Tower, the tallest building in the UK, on Thursday, September 26, 2013 in London. The Minnesota Vikings and Pittsburgh Steelers will play at Wembley Stadium on Sunday. (Dave Shopland/NFL)

Minnesota Vikings cheerleaders at the top of the Shard Tower, the tallest building in the UK, on Thursday, September 26, 2013 in London. The Minnesota Vikings and Pittsburgh Steelers will play at Wembley Stadium on Sunday. (Dave Shopland/NFL)

Minnesota Vikings cheerleaders pose for a photograph during a photo shoot on Regent Street in London. (Dave Shopland/NFL)

Minnesota Vikings cheerleaders pose for a photograph during a photo shoot on Regent Street in London. (Dave Shopland/NFL)

Vikings Brian Robison practices with the tackle dummies at the Vikings' UK base in Chandler's Cross, Hertfordshire, UK on Thursday, September 26, 2013. (Sean Ryan/NFL)

Vikings Cordarrelle Patterson runs the ball back during practice at the Vikings' UK base in Chandler's Cross, Hertfordshire, UK on Thursday, September 26, 2013. (Sean Ryan/NFL)

Vikings Adrian Peterson during practice at the Vikings' UK base in Chandler's Cross, Hertfordshire, UK on Thursday, September 26, 2013. (Sean Ryan/NFL)

Vikings quarterbacks Christian Ponder, Matt Cassel and McLeod Bethel-Thompson chat during todays practice session at the Vikings' UK base in Chandler's Cross, Hertfordshire, UK on Thursday, September 26, 2013. (Sean Ryan/NFL)

(L-R) Minnesota Vikings quarterbacks Matt Cassel and Christian Ponder chat during practice at the Vikings' UK base in Chandler's Cross, Hertfordshire, UK on Thursday, September 26, 2013. (Sean Ryan/NFL)

Minnesota Vikings head coach Leslie Frazier looks on during practice at the Vikings' UK base in Chandler's Cross, Hertfordshire, UK on Thursday, September 26, 2013. (Sean Ryan/NFL)

Vikings running back Adrian Peterson catches a few pass during practice at the Vikings' UK base in Chandler's Cross, Hertfordshire, UK on Thursday, September 26, 2013. (Sean Ryan/NFL)

Minnesota Vikings Chad Greenway talks to the press prior to practice at the Vikings' UK base in Chandler's Cross, Hertfordshire, UK on Thursday, September 26, 2013. (Sean Ryan/NFL)

A Minnesota Vikings cheerleader poses for a photograph during a photo shoot on Regent Street in London. (Dave Shopland/NFL)

Minnesota Vikings cheerleaders pose for a photograph during a photo shoot on Regent Street in London. (Dave Shopland/NFL)

Minnesota Vikings cheerleaders pose for a photograph during a photo shoot on Regent Street in London. (Dave Shopland/NFL)

Minnesota Vikings cheerleaders pose for a photograph during a photo shoot on Regent Street in London. (Dave Shopland/NFL)

Minnesota Vikings player graphics are installed at Wembley stadium in preparation for the 2013 NFL International series game between the Pittsburgh Steelers and the Minnesota Vikings on Sunday, September 29. (Sean Ryan/NFL)

Adrian Peterson of the Vikings, poses with a gigantic photograph of him self on the side of Wembley stadium behind him. Players and cheerleader from the Vikings stage football and cheerleading coaching clinics with London children on Sept. 24, 2013. (Sean Ryan/NFL)

NFL flags line Regent Street in London in preparation for the international football game between the Pittsburgh Steelers and the Minnesota Vikings at Wembley Stadium. (Dave Shopland/NFL)

NFL flags line Regent Street in London in preparation for the international football game between the Pittsburgh Steelers and the Minnesota Vikings at Wembley Stadium. (Dave Shopland/NFL)

A sightseeing bus makes its way down Regent Street in London amid NFL flags in preparation for the international football game between the Pittsburgh Steelers and the Minnesota Vikings at Wembley Stadium. (Dave Shopland/NFL)

Head coach Leslie Frazier (R) and Cordarrelle Patterson. Players and cheerleader from the Vikings stage football and cheerleading coaching clinics with London children on Sept. 24, 2013. (Sean Ryan/NFL)

Greg Jennings of the Vikings interacts with kids as players and cheerleader from the Vikings stage football and cheerleading coaching clinics with London children on Sept. 24, 2013. (Sean Ryan/NFL)

Greg Jennings of the Vikings interacts with kids as players and cheerleader from the Vikings stage football and cheerleading coaching clinics with London children on Sept. 24, 2013. (Sean Ryan/NFL)

Players and cheerleader from the Vikings stage football and cheerleading coaching clinics with London children on Sept. 24, 2013. (Sean Ryan/NFL)

Head coach Leslie Frazier coaches kids as players and cheerleader from the Vikings stage football and cheerleading coaching clinics with London children on Sept. 24, 2013. (Sean Ryan/NFL)

Adrian Peterson talks with kids as players and cheerleader from the Vikings stage football and cheerleading coaching clinics with London children on Sept. 24, 2013. (Sean Ryan/NFL)

Players and cheerleader from the Vikings stage football and cheerleading coaching clinics with London children on Sept. 24, 2013. (Sean Ryan/NFL)

Jared Allen and the Minnesota Vikings arrive at Gatwick Airport in London on Sept. 24, 2013. (Dave Shopland/NFL)

Christian Ponder and the Minnesota Vikings arrive at Gatwick Airport in London on Sept. 24, 2013. (Dave Shopland/NFL)

Jared Allen and the Minnesota Vikings arrive at Gatwick Airport in London on Sept. 24, 2013. (Dave Shopland/NFL)

People walk past Wembley Stadium in London, Tuesday Sept. 24, 2013. The Pittsburgh Steelers are to play the Minnesota Vikings in the NFL International Series at Wembley Stadium in London on Sunday, Sept 29. (Sean Ryan/NFL)

The Minnesota Vikings practice at their UK base in Chandler's Cross Hertfordshire,The Grove. The Minnesota Vikings will play the Pittsburgh Steelers in the 2013 NFL International Series at Wembley Stadium in London on September 29, 2013. (Sean Ryan/NFL)

Minnesota Vikings Christian Ponder practices at UK base in Chandler's Cross Hertfordshire, London. (Sean Ryan/NFL)

Minnesota Vikings running back Adrian Peterson (28) takes a handoff from quarterback Christian Ponder (7) during practice at their UK base in Chandler's Cross Hertfordshire, London. (Sean Ryan/NFL)

Minnesota Vikings quarterback Matt Cassel (16) throws the ball in front of McLeod Bethel-Thompson (4) during practice at their UK base in Chandler's Cross Hertfordshire, London. (Sean Ryan/NFL)

Minnesota Vikings owner and president Mark Wilf answers questions from the media following practice at their UK base in Chandler's Cross Hertfordshire, London. (Sean Ryan/NFL)

Minnesota Vikings running back Adrian Peterson (28) answers questions from the media following practice at their UK base in Chandler's Cross, London. (Sean Ryan/NFL)

Steelers head coach Mike Tomlin organizes his players during practice at Wasps rugby football training ground, London. (Sean Ryan/NFL)

Steelers head coach Mike Tomlin organizes his players during practice at Wasps rugby football training ground, London. (Sean Ryan/NFL)

The Pittsburgh Steelers at Wasps rugby football training ground, London in preparation for their 2013 International game against the Minnesota Vikings. (Sean Ryan/NFL)

Pittsburgh Steelers strong safety Troy Polamalu (43) arrives for practice at Wasps rugby football training ground, London. (Sean Ryan/NFL)

Pittsburgh Steelers wide receiver Antonio Brown (84) stretches before practicing at Wasps rugby football training ground, London. (Sean Ryan/NFL)

Steelers quarterback Ben Roethlisberger (7) throws during practice at Wasps rugby football training ground, London. (Sean Ryan/NFL)

Former NFL players Daunte Culpepper, Merril Hodge, and sportscaster Ahmad Rashad, answer questions from fans during the NFL International Series Fan Forum in London on September 28, 2013. (Sean Ryan/NFL)

Fans in player jerseys look on during an NFL International Series Fan Forum in London on September 28,2013. (Sean Ryan/NFL)

Former NFL players Daunte Culpepper, Merril Hodge, and sportscaster Ahmad Rashad, answer questions from fans during the NFL International Series Fan Forum in London on September 28, 2013. (Sean Ryan/NFL)

Fans line Regents Street during a block party in preparation for the 2013 NFL International Series game between the Pittsburgh Steelers and the Minnesota Vikings in London on Sunday, Sept 29, 2013. (Sean Ryan/NFL)

Fans line Regents Street during a block party in preparation for the 2013 NFL International Series game between the Pittsburgh Steelers and the Minnesota Vikings in London on Sunday, Sept 29, 2013. (Sean Ryan/NFL)

Pittsburgh Steelers quarterback Ben Roethlisberger (7) and cornerback Ike Taylor (24) are interviewed during the NFL Regents Street Block Party on Saturday, September 29, 2013. (Sean Ryan/NFL)

Fans take photos during the NFL Regents Street Block Party in London on Saturday, September 28, 2013. (Sean Ryan/NFL)