You know, I've been thinking.
In the time of the Prophet (pbuh), we had a certain range of sports - horse riding, archery, playing with your wife (?) - occasionally wrestling and foot racing.
The interesting thing here is that none of these were team sports.
When did team sports first arise?
Team sports tend to be regimented - captains lead, everyone else plays by the rules. Infringements upon these rules lead to penalties which directly affect your team.
Thus as people grow up playing these sports, they become used to having people in authority and following this authority for optimal outcomes - they learn to respect authority which delivers the correct results. They learn to work as part of a collective.
The physical aspect is regulated by the rules - it's channeled by these in a similar way to that which Omar indicated. You don't have to beat up someone physically to alleviate pent up aggression (although this does happen, there are appropriate punishments), instead you can add a level of abstraction and relieve this tension by channeling it - teaching you to channel your energies towards a given task.
This is probably one of the reasons why sports such as football, once organised in a coherent way with a decent structure, are so effective within developing inner city areas where the children unfortunately often lack authority figures/control. This may also explain why Brazilians aren't good team players - there is no structure in the favelas as the government has other pressing concerns.
As we move this from the microsocial level to the national level, we can see how sport acts as a remarkably effective social control - anyone in England can walk through the streets of any major town during England's game against Croatia and they will find the streets absolutely empty as national pride (again an interesting contsruct) intermingles with the instilled values delivered by growing up playing a nice game of soccer - there are endless talks about tactics and form, every aspect of a relatively simple game analysed ad extremum as it captures the public imagination