Sinfield, who led a team which raised over £2.7m by completing seven marathons in seven days in December last year, said: "Undoubtedly this will the toughest challenge I have ever attempted, but I know it will mean so much to so many people if we can reach our fundraising target. In the past an underperforming defense might have been disguised and rescued by the magic on the other side of the ball, which has faded slightly but by no means fizzled out overnight. It will be back. Please use Chrome browser for a more accessible video player & Sky Sports - on the go! Available to download now on -iPhone & iPadandAndroid©2021 Sky UKFootball