Call the shots? (3)
I believe the answer is:
ref
'call the shots?' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ref that I've seen before include "In brief, a soccer controller" , "Football's whistler" , "Middleman needing cards" , "A diminutive umpire in soccer or boxing" , "Sports umpire" .)