运动员从事某项球类运动的年数amount of experience one has in playing a ball sport

• 这些半大孩子的球龄起码有五年。

  These teenagers must have at least 5 years of playing experience.

• 场上两名主力年轻队员球龄都才两年。

  The two leading young players on the court have only two years of experience.