Thats on you, if you have the choice always send later. Proven that older kids in the class will be ahead and therefore pick up more developmental opportunities. So if youre just getting around to figuring out how to best position your kid because of Lacrosse you have bigger issues.
This obviously does not come from an educator. There are countless studies that holding your child back when they are developmentally ready to start school is actually detrimental to their academic development. | 
