3. Roy Keane
Keane was one of the most dominant midfielders of his generation. The Irishman played a crucial role in helping his country qualify for the 2002 World Cup. However, he played a central role in one of the most notorious bust-ups in soccer history (via Mirror).
The Manchester United star stormed out of their camp in Saipan. He left his teammates high and dry because he thought the organization was unprofessional.