As far as sports are concerned, I don't think there is really any replacement for speed. There are tons of guys who are strong, but the thing that seperates great players from average ones is speed.
With that said... the reason most high schoolers are slow is that they are weak. If this kid is 170# and can squat 350#, than he needs speed training. If he squats 150#, he needs to get stronger. Again, that's most likely the case, it's different for everybody though.