A club player (6)
I believe the answer is:
golfer
'a club player' is the definition.
'golfer' can be an answer for 'player' (golfer is a kind of player). I am not certain of the 'a club' bit.
'club player' is the wordplay.
'club' becomes 'golf club' (golf club is a kind of club).
'player' becomes 'er' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'golf'+'er'='GOLFER'
Can you help me to learn more?
(Other definitions for golfer that I've seen before include "Player on links" , "McGinley or Harrington, say" , "Player with clubs and tees" , "Swinger on course" , "Driver, chipper and putter" .)