Retort from S Warne upset rugby player (6,4)
I believe the answer is:
answer back
'retort' is the definition.
(synonyms)
's warne upset rugby player' is the wordplay.
'upset' indicates an anagram.
'rugby player' becomes 'back' (type of rugby player).
's'+'warne'='swarne'
'swarne' is an anagram of 'answer'.
'answer'+'back'='ANSWER BACK'
'from' is the link.
(Other definitions for answer back that I've seen before include "Be impertinent" , "Retort" , "reply impertinently" , "Reply pertly" .)