Am I correct in assuming, that by "Team sports" It HAS to be a team vs team sport? No People have to be involved, right?
i think what they mean by no people have to be involved is that you can take a picture of a soccer ball without having to have soccer players in the shot...
Team sports: Hockey, football, soccer, baseball, volleyball, basketball, cricket, etc.
Not team sports: skiing, motocross, tennis (although doubles could sneak in there), ping-pong, etc.
The description seems pretty clear. You need not shows multiple players. Showing a kid playing soccer all by himself would qualify, I think, as it is a soccer ball and soccer is a team sport.
The subject is good, the location is bad. Take the same subject and put him in a field, especially with other "symbols" of a soccer field such as a goal or field markings, and it would do fine. Its not that what you took was "wrong" per se, just that as moodville pointed out, the impression you get when you see the car and the sidewalk is a lone kid playing, not the team sport of soccer. Just a suggestion...
(edit) Oh, and a uniform - a "hallmark" of team sports - wouldn't hurt.