In-Season training is VITAL for HS teams. Even if its just once a week for 30 minutes, exercises can push (slowly) the needle in the right direction.
With programs that are on tight schedule splits like this, we typically pick:
-1 Power exercise. Usually loaded jumps due to how simple and effective they are.
-1 Main upper + 1 accessory. I usually stick with a heavy/low volume press as our main lift and then a pulling/rowing accessory.
-1 Main lower + accessory. I defer to heavy/low volume TBDL or a box squat simply because its easy to do/set up and does not leave athletes sore compared to split squats, back squats, rdl, etc... Accessory wise, I love a simple goblet squat, lateral squat or SL RDL (further away from game days).
It's not much, but 14-16 weeks of the above is better than 14-16 weeks off!