Prunes will have to manage (3)
I believe the answer is:
run
'manage' is the definition.
(I've seen this before)
'prunes will have' is the wordplay.
'have' indicates a hidden word.
'RUN' is hidden within 'prunes will'.
'to' acts as a link.
(Other definitions for run that I've seen before include "Move fast with the hens?" , "On the . . . - fleeing from pursuit" , "Manage; flee" , "Card sequence in suit" , "Manage, operate" .)