Mike in returning role as vagrant (5)
I believe the answer is:
tramp
'vagrant' is the definition.
(I know that vagrant can be written as tramp)
'mike in returning role' is the wordplay.
'mike' becomes 'M' (phonetic alphabet: alpha, bravo, charlie etc.).
'in' indicates putting letters inside.
'returning' says the letters should be written backwards.
'role' becomes 'part' (eg a part or role in a film).
'part' reversed gives 'trap'.
'm' placed within 'trap' is 'TRAMP'.
'as' is the link.
(Other definitions for tramp that I've seen before include "Hike" , "Traveller" , "Walk heavily, as when weary, or through mud" , "Walk heavily like hobo" , "Vagrant, long walk" .)