Turn provided by senior cricketer (7)
I believe the answer is:
fielder
'cricketer' is the definition.
(fielder is a kind of cricketer)
'turn provided by senior' is the wordplay.
'turn' says the letters should be written in reverse.
'provided' becomes 'if' (eg 'provided it's sunny' means 'if it's sunny').
'by' means one lot of letters go next to another.
'senior' becomes 'elder' (synonyms).
'if' backwards is 'fi'.
'fi'+'elder'='FIELDER'
(Other definitions for fielder that I've seen before include "Slip, perhaps" , "he might be in a silly position" , "Slip or cover, maybe" , "One as cover, slip" , "Cricketing slip, say?" .)