I think with a few more reps, he'll be fine. You can't teach leg strength.. but you can teach mechanics. I can kick (or at least in the past) a 60 yard filed goal.. but can't get a punt to go past 20 yards to save my life. Later I discovered it was because my leg was too fast for my own good.. it's almost like a batter swinging too quickly... and fouls the ball instead of driving it down the middle....