Color me ignorant, but I didn't realize there was a professional lacrosse league in the
USA. Mind if I ask where you're located?
You got me curious enough to call a few of my companies. At least in Georgia, Golden Rule (United Health One) will consider your client for coverage. However, they won't cover any injuries sustained at an official practice or game. Since it looks like he's got supplemental coverage for that, you should be good to go!