Manchester United fan wouldn't save his City-supporting brother's life unless he also turned completely red

It's not so strange to have members of a family support different teams, but it may be strange to realize what football fans are prepared to do to prove that their team is the one worth supporting.

As Ole-Gunnar Solskjaer and Pep Guardiola prepare to lead their teams to yet another Manchester Derby, we'll take you back to 2003 to show you how strong is the rivalry of Manchester United and Manchester City.

A die-hard United fan Martin Warburton agreed to give his City-supporting brother Paul a life-saving transplant but only if he becomes a United fan. Martin and Paul grew up together in Manchester in the 1970s with their parents. Everyone in the house were City fans – except Paul. For some reason, he decided that he would be a Red Devils fan. And many years later, he got a chance to turn his elder brother Paul to the red half of the city.

Paul was battling a rare form of leukaemia for a few years until the doctors said that he needed a bone marrow transplant in 2003. The best possible donor was his brother. Of course, Martin was happy to help his brother fight illness – but he also had a wicked idea to add another chapter to the never-ending story of a football rivalry.

Martin made Paul sign a contract ordering him to pledge his support for the team he hates in return for being a donor of matching red stem cells. Paul was stunned by the proposal, but he had to agree and sign. Some things are more important than football after all.

Paul had backed the Sky Blues for 50 years but he vowed to support United in future – and not only that! He was even obliged to wear red socks and paint the inside of his house red. Martin saw it as a good laugh and a way to boost the morale in his family. Although, he might have left his brother's love for City alone!

"This was the perfect chance to get Paul to stop backing the Blues and switch over to the almighty Reds. I drew up a contract for him to sign, saying he would totally support United. I just hope now it will save his life.''

It's just one of many stories you hear from silly football fans in England. We're hoping for a good game and more stories to tell. And this time, hopefully no lives will depend on the match.

Many years later, the stature of the clubs has changed. City have become one of the best teams in Europe and have made the Manchester Derby important even to the people who aren't from this city.

United's striker Edinson Cavani wants his team to leave a mark on the football history of Manchester.

"I understand perfectly well what these games mean, and I feel just how significant a derby is for a club and its fan-base. I think there are some games that are really special, because of all the history behind them and the rivalry that exists with the other club. They are the kind of games that I think everyone wants to be involved in."

City's Portuguese winger Bernardo Silva believes that possession will prove the key for getting one over the Red Devils.

"I think mostly controlling the game with the ball, because we know how dangerous they are. With players like Cavani and Ronaldo and when they have chances, they're lethal. They don't need much space to score. The only way to avoid them creating chances is with the ball, is having the ball as much as we can and trying to put them in the final third to try to prevent the counter-attacks as much as possible."

Get hyped for the big game!