So you suddenly have a sports fan on your hands. His enthusiasm is great -- the hours spent watching TV from the couch, maybe not so much. Rather than trying to talk him out of his hobby, make the most of it:
Focus on family bonding
When Carol DeGregorio's son Edward, of Port Jefferson Station, NY, began to show a serious interest in the New York Yankees, he got to spend quality time with his dad while talking batting averages.
Encourage the info-quest
Following statistics, sussing out the players' backgrounds, and collecting player cards all offer learning opportunities.
Point out good values
The occasional good-player-gone-bad conversation will probably be necessary, but for the most part, take advantage of the chance to underscore positive qualities, such as teamwork and discipline.
Of course, fandom can't be everything. Make sure your child is exercising or playing sports, as well.