Servant left abandoned by someone playing game (5)
I believe the answer is:
gofer
'servant' is the definition.
'left abandoned by someone playing game' is the wordplay.
I cannot really understand how this works, but
'game' could be 'go' (go game is a kind of game) and 'go' is present in the answer.
This explanation may well be incorrect...
(Other definitions for gofer that I've seen before include "Assistant who runs errands (slang)" , "Forge (anag.)" , "Errand boy" , "Menial assistant" , "One running errands" .)