For each erstwhile player (9)
I believe the answer is:
performer
'player' is the definition.
(I've seen this before)
'for each erstwhile' is the wordplay.
'for each' becomes 'per' (per person).
'erstwhile' becomes 'former' (synonyms).
'per'+'former'='PERFORMER'
(Other definitions for performer that I've seen before include "clown possibly" , "Such as a musician or actor" , "star?" , "Entertainer" , "Eg 9 [ACTRESS]" .)