Earlier, in front of worker (10)
I believe the answer is:
beforehand
'earlier' is the definition.
(beforehand can mean earlier)
'in front of worker' is the wordplay.
'in front of' becomes 'before' (standing before means standing in front of).
'worker' becomes 'hand' (hand is a kind of worker).
'before'+'hand'='BEFOREHAND'
(Other definitions for beforehand that I've seen before include "Previously" , "In advance" , "Earlier" .)