One fielding six balls, in this sweater? (8)
I believe the answer is:
slipover
'this sweater?' is the definition.
(slipover is a kind of sweater)
'one fielding six balls' is the wordplay.
'one fielding' becomes 'slip' (cricket position).
'six balls' becomes 'over' (cricket).
'slip'+'over'='SLIPOVER'
'in' is the link.
(Other definitions for slipover that I've seen before include "Top" , "knitted garment" .)