Difficult position? Best to roll over (4)
I believe the answer is:
spot
'difficult position?' is the definition.
(a spot is a difficult or problematic situation)
'best to roll over' is the wordplay.
'best' becomes 'tops'.
'to roll over' says the letters should be written in reverse (I've seen 'rolling over' mean this).
'tops' written backwards gives 'SPOT'.
(Other definitions for spot that I've seen before include "Mark, dot" , "Dirty blemish" , "See 5" , "See; eruption" , "Difficult situation" .)