Players press - it's hard to beat (4-4)
I believe the answer is:
cast-iron
'hard to beat' is the definition.
'players press' is the wordplay.
'players' becomes 'cast' (I've seen this before).
'press' becomes 'iron' (ironing is a kind of pressing).
'cast'+'iron'='CAST-IRON'
'it's' is the link.
(Other definitions for cast-iron that I've seen before include "Extremely robust" , "Unassailable" , "Very strong" , "Firm and unchangeable" , "Rigid, unyielding" .)