Aloofness shown by spare player? (7)
I believe the answer is:
reserve
I believe this clue is a triple definition!
'aloofness' is the first definition.
(thesaurus)
'shown by' acts as a link.
'spare' is the second definition.
(synonyms)
'player?' is the third definition.
(I've seen this before)
(Other definitions for reserve that I've seen before include "put to one side" , "Keep for someone - spare bod" , "Conservation area" , "not in the front line" , "Keep for future use" .)