Summer ball is a must. However, he needs to play on a team that will consider the wear and tear he has placed on his arm during the high school season. I have managed a 17-18 team for 15 years. My pitching coach has always insisted that the first 2 to 3 outings a starting pitcher has for us, the pitcher will be limited to between 60-75 pitches. Exceptions are often made however, but not in the area of increasing pitch counts. If one of our pitchers start 10 games in H.S. (in MD), he has pitched every other game. When this happens, our pitching coach usually requires that he pitch even less at the start of a season. We pride ourselves on winning summer league championships the last 5 weeks of the season, not the first 3. Good Luck!