I'm a bit late on answering this, but please, please, please, take this very seriously. Don't let him back to activities prematurely.
I got a bad concussion when I was 7 and have had migraines ever since and developed seizures as an adult.
My son got two concussions last year, the first was bad, the second was mild, but they are not separate, they are additive. Once you have one, you can never erase it, you have to be very careful.
My son developed post-concussion syndrome after the second one and it's very serious. He hallucinated and had depression and anxiety.
I would limit contact sports for much longer than 1 week, try 6 months! If he gets hit again, that would be awful.
Also, just an fyi, Zofran creates agitation, it would be better just for him to rest.
If you are interested, since you are in Long Beach, you might want to take him to a concussion specialist if any of the symptoms persist. We went to a satellite office for Children's Hospital LA in Torrance and the doctor there was excellent! Dr. Bianca Edison.
Ultimately, my son had to take two months off of doing any computer screens, sports, etc., and then slowly work his way back to "normal". He can no longer play competitive contact sports, the risk is too great, so he plays recreationally instead where he isn't in such an intense environment and likely to get hurt again. We don't keep him in a bubble, but he now plays non-checking ice hockey, and does not play varsity sports in high school anymore, and ALWAYS wears a helmet when he skateboards.