Sent in to disrupt game (6)
I believe the answer is:
tennis
'game' is the definition.
(I know that tennis is a type of court game)
'sent in to disrupt' is the wordplay.
'to disrupt' is an anagram indicator (I've seen 'disrupting' mean this).
'sent'+'in'='sentin'
'sentin' anagrammed gives 'TENNIS'.
(Other definitions for tennis that I've seen before include "Sent in to play the game, oddly" , "Sent in, strangely, for sport" , "Racket-and-ball game" , "Pete Sampras's sport" , "Sport with grand slams?" .)