Named don working whenever required (2,6)
I believe the answer is:
on demand
'whenever required' is the definition.
(I've seen this before)
'named don working' is the wordplay.
'working' is an anagram indicator.
'named'+'don'='nameddon'
'nameddon' anagrammed gives 'ON DEMAND'.
(Other definitions for on demand that I've seen before include "As soon as requested" , "Whenever required" , "As soon as required" , "When asked for" .)