Worker may be bananas (4)
I believe the answer is:
hand
This clue is a double definition.
'worker' is the first definition.
(hand is a kind of worker)
'be bananas' is the second definition.
(I've seen this before)
'may' acts as a link.
(Other definitions for hand that I've seen before include "Hired worker" , "Unit of equine measurement" , "Cards dealt to player" , "Script" , "Pointer; workman" .)