Hazel’s maybe about to hit for six? (4)
I believe the answer is:
stun
'hit for six?' is the definition.
(to hit for six can informally mean to astonish)
'hazel's maybe about' is the wordplay.
'hazel's maybe' becomes 'nuts' (hazelnut is a type of nut).
'about' shows that the letters should be reversed in order.
'nuts' backwards is 'STUN'.
'to' acts as a link.
(Other definitions for stun that I've seen before include "floor" , "Daze, overwhelm" , "Stupefy - daze" , "Take aback" , "Stagger, amaze" .)