Fans arrive at Wembley Stadium before the NFL football game between the Atlanta Falcons and the Detroit Lions in London, Sunday, Oct. 26, 2014. (AP Photo/Matt Dunham)

A football fan smiles during the NFL Fan Rally in Trafalgar Square, London, Saturday, Oct. 25, 2014. (AP Photo/Tim Ireland)

Young football fans play with a ball during the NFL Fan Rally in Trafalgar Square, London, Saturday, Oct. 25, 2014. (AP Photo/Tim Ireland)

The Atlanta Falcons Drumline perform during the NFL Fan Rally in Trafalgar Square, London, Saturday, Oct. 25, 2014. (AP Photo/Tim Ireland)

A Detroit Lions fan smiles during the NFL Fan Rally in Trafalgar Square, London, Saturday, Oct. 25, 2014. (AP Photo/Tim Ireland)

Football fans cheer during the NFL Fan Rally in Trafalgar Square, London, Saturday, Oct. 25, 2014. (AP Photo/Tim Ireland)

Football fans pose for a picture in Trafalgar Square, London, Saturday, Oct. 25, 2014. (AP Photo/Tim Ireland)

An Atlanta Falcons fan dances during the NFL Fan Rally in Trafalgar Square, London, England, Saturday, Oct. 25, 2014. (AP Photo/Tim Ireland)

Atlanta Falcons cheerleaders perform during the NFL Fan Rally in Trafalgar Square, London, England, Saturday, Oct. 25, 2014. (AP Photo/Tim Ireland)

A Detroit Lions fan gestures as the Atlanta Falcons team arrive during the NFL Fan Rally in Trafalgar Square, London, England, Saturday, Oct. 25, 2014. (AP Photo/Tim Ireland)

A football fan carries the refreshments during the NFL Fan Rally in Trafalgar Square, London, Saturday, Oct. 25, 2014. (AP Photo/Tim Ireland)

Signatures on a Detroit Lions fan helmet during the NFL Fan Rally in Trafalgar Square, London, Saturday, Oct. 25, 2014. (AP Photo/Tim Ireland)

Football fans wave flags in Trafalgar Square, London, Saturday, Oct. 25, 2014. London's National Gallery of art in background. (AP Photo/Tim Ireland)