Class players? Last in league! (5)
I believe the answer is:
caste
'class' is the definition.
(caste is a kind of class)
'players? last in league' is the wordplay.
'players?' becomes 'cast' (I've seen this before).
'last in' says to take the final letters.
The final letter of 'league' is 'e'.
'cast'+'e'='CASTE'
(Other definitions for caste that I've seen before include "Group within society" , "Hereditary social class among Hindus" , "Brahmans for instance" , "Social system" , "place in society" .)