By ANNE M. PETERSON
AP Sports Writer
The gradual buildup of Major League Soccer’s academy system over the past decade has led to an increasingly young talent pool. There will be plenty of young players to watch when the MLS season kicks off Saturday. Real Salt Lake’s Axel Kei is the youngest newcomer to the league, at just 14. Other teenagers getting attention across MLS are San Jose’s Cade Cowell, Chicago’s Gabriel Slonina and Philadelphia’s Paxten Aaronson.