noun
veteran player; experienced player
Used in sports contexts for a player with about ten years of experience, implying seasoned skill.
彼は十年選手としてチームを引っ張っている。
As a veteran player, he leads the team.
noun
Extended from sports to any profession; refers to someone with about ten years of experience in a field.
彼女はこの業界では十年選手だ。
She is a veteran in this industry.
ベテラン is a general loanword for 'veteran' in any field, while 十年選手 specifically implies about ten years of experience and is often used in sports or job contexts.
Compound of 十年 (ten years) and 選手 (player, athlete). Originally a sports term, it later extended to any profession.