Fellows had briefly to be put right (4)
I believe the answer is:
mend
'be put right' is the definition.
(I've seen this before)
'fellows had briefly' is the wordplay.
'fellows' becomes 'men' (fellow can mean a man).
'had briefly' becomes 'd' (d is a shortened version of had - e.g. 'she'd').
'men'+'d'='MEND'
'to' is the link.
(Other definitions for mend that I've seen before include "Fix, repair" , "Heal" , "'Restore, fix (4)'" , "Make improvements" , "Return to health; repair" .)