Cattle worker runs into Kent port (6)
I believe the answer is:
'cattle worker' is the definition.
'runs into kent port' is the wordplay.
'runs' becomes 'r' (cricket abbreviation).
'into' means one lot of letters goes inside another.
'kent port' becomes 'dover' (I've seen this before).
'r' inserted into 'dover' is 'DROVER'.
(Other definitions for drover that I've seen before include "Hugh the --, opera by Vaughan Williams", "One driving cattle", "One driving flock to market", "Person moving sheep or cattle from one place to another", "Cattle hand".)