Foremost of players to speak in golf club (6)
I believe the answer is:
putter
'golf club' is the definition.
(I've seen this before)
'foremost of players to speak' is the wordplay.
'foremost of' says to take the initial letters.
'to' is a charade indicator (letters next to each other).
'speak' becomes 'utter' ('utter' can be a synonym of 'speak').
The first letter of 'players' is 'p'.
'p'+'utter'='PUTTER'
'in' is the link.
(Other definitions for putter that I've seen before include "Club to use on the green" , "Club used on the green" , "Golf-club" , "Type of golf club" , "Golf club used on greens" .)