Cavan Sullivan becomes youngest in US major sports to make pro debut USA TODAYSullivan, 14, bests Adu, youngest to play in MLS ESPNPhiladelphia Union midfielder Cavan Sullivan is the youngest ever in MLS. He’s just 14 years old The Associated PressPhiladelphia’s Cavan Sullivan, 14, breaks Freddy Adu’s youngest MLS player mark The GuardianCavan Sullivan, 14, breaks Freddy Adu’s record, debuts in an evolved MLS Yahoo Sports