Никак не сможет. Почитайте полностью вопрос - спрашивают про ЭХ.
Да и если говорить о турнирах USTA , 5 и 30 - не имеет никакой разницы. Значение имеет месяц рождения:
The USTA uses a "month of birth" age eligibility rule for junior players competing in USTA sanctioned tournaments. This rule applies to all local, District, Sectional, and National USTA sanctioned tournaments – it does not apply to USTA International Tournaments and ITF Tournaments. Junior players may continue to play in the 12, 14, 16 and 18 age divisions until the month they turn 13, 15, 17, or 19, respectively.
USTA International Tournaments and ITF Tournaments use a "year of birth" age eligibility rule. Juniors may play the 18s, 16s, 14s or 12s division until the year in which they turn 13, 15, 17, or 19 respectively.