Holding trump, not played as first card, and not bothered (9)
I believe the answer is:
unruffled
'not bothered' is the definition.
(I know that unruffled is the opposite attribute of bothered)
'holding trump not played as first card' is the wordplay.
'holding' means one lot of letters goes inside another.
'trump' becomes 'ruff' (synonyms).
'not played as first card' becomes 'unled' (lead can mean to play the first card in card games).
'ruff' put into 'unled' is 'UNRUFFLED'.
'and' is the link.
(Other definitions for unruffled that I've seen before include "Not disturbed, remaining even-tempered" , "Tranquil, unperturbed" , "Not perturbed" , "without frills" , "Composed" .)