"Head-butting your rival or stamping on their nuts does not do the brand much good," says Nick Brown, group director of the advertising and PR agency Golley Slater.
So who's next?
According to the Guardian, the hottest brands in 2010 might be:
Freddy Adu USA, 17
Already bagged the biggest Major League Soccer sponsorship deal with Nike. Needs European move to exploit his image rights fully.
Cesc Fábregas, Spain, 19
Heir to Raúl as the golden boy of Spanish football, a position rarely held by a Catalan. A transfer to Real Madrid would bring other suitors to rival his Nike contract.
Lionel Messi, Argentina, 18
Maradona thinks he will be the best in the world by 2010. Signed £5m six-year Adidas contract in March.
Wayne Rooney, England, 20
Some question him as a role model, though that has not put off Nike, Coca-Cola, Asda and EA Sports.
Ronaldinho, Brazil, 26
Age cannot wither his income from Barcelona, Pepsi, Nike and Cadbury estimated at £33m over the next four years.
John Terry, England, 26
Sponsors flock to the captain but so far he has only King of Shaves to complement Umbro boot deal.