He's a rubbish worker and must get reassigned (7)
I believe the answer is:
dustman
'he's a rubbish worker' is the definition.
(someone who takes away rubbish)
'and must get reassigned' is the wordplay.
'get reassigned' indicates an anagram (letters are assigned new positions).
'and'+'must'='andmust'
'andmust' is an anagram of 'DUSTMAN'.
(Other definitions for dustman that I've seen before include "Refuse collector" , "Refuse worker" , "I clear what's left" , "Garbage collector" , "My old man's occupation" .)