For protection, you need a bit of spadework (3)
I believe the answer is:
pad
'for protection' is the definition.
(thesaurus)
'a bit of spadework' is the wordplay.
'a bit of' says the answer is hidden in the clue.
'PAD' is hidden in the letters of 'spadework'.
'you need' is the link.
(Other definitions for pad that I've seen before include "Residence" , "wearing this?" , "Batsman's protection" , "It's found on an animals's foot and a cricketer's leg" , "Footprint - home of one's own (slang)" .)