The phrase "amateur players" refers to people who engage in an activity or sport as a hobby or for fun, rather than as a professional or someone who makes a living from it. Full definition
Once the money was removed for everyone but the highest draft picks, it became harder and harder for amateur players to get the support and development they needed. (sbnation.com)
His record shows bunch of wins but they are against amateur players and very small nations. (sbnation.com)
At 18 he was regarded as the nation's best amateur player. (si.com)