D.G.
Any early childhood education expert will tell you organized sports are for parents not preschoolers! Children do not think like adults so competion, rules and games are not developmentally appropriate for children before age 6 to 8. They will enjoy organized sports much more if you wait until they are ready. Listen to an expert talk on the subject at this link:
http://www.jackstreet.com/jackstreet/WMBK.Coakley.cfm