Stage favourites making comeback (4)
I believe the answer is:
step
'stage' is the definition.
(as in a step or stage of a process)
'favourites making comeback' is the wordplay.
'favourites' becomes 'pets' ('pet' can be a synonym of 'favourite').
'making comeback' says the letters should be written in reverse.
'pets' backwards is 'STEP'.
(Other definitions for step that I've seen before include "Place foot on as with a pest" , "Stride" , "Move a little way" , "'Stage, rung (4)'" , "Put foot on a pest" .)