The net's in a different position for this! (6)
I believe the answer is:
tennis
'position for this' is the definition.
The definition suggests a singular noun which matches the answer.
'the net's in a different' is the wordplay.
'a different' indicates anagramming the letters (letters placed in a different order).
'nets'+'in'='netsin'
'netsin' anagrammed gives 'TENNIS'.
Can you help me to learn more?
(Other definitions for tennis that I've seen before include "Racket-and-ball game" , "Net sport" , "- elbow; - shoe" , "Medieval, originally French, sport, codified by the British" , "Sport Dwight Davis gave trophy for" .)