Supporter keeping log to stimulate setter perhaps (7)
I believe the answer is:
firedog
'supporter keeping log' is the definition.
(supporter holding a log in a fireplace)
'stimulate setter perhaps' is the wordplay.
'stimulate' becomes 'fire' (fire or fire up can mean to stimulate).
'setter perhaps' becomes 'dog' (setter is a type of dog).
'fire'+'dog'='FIREDOG'
'to' is the link.
(Other definitions for firedog that I've seen before include "Hearth support" , "hearth fixture" , "bar by the grate" , "Andiron" , "Enthuse boxer, say" .)