Gretzky, once (5)
I believe the answer is:
oiler
'gretzky once' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for oiler that I've seen before include "Device that lubricates" , "If not well" , "Loire (anag.)" , "Grease monkey" , "One applying lubricant" .)