Make pro say: 'Making a comeback' (5)
'make' is the definition.
(forging is a kind of making)
'pro say making a comeback' is the wordplay.
'pro' becomes 'for' (I've seen this before).
'say' becomes 'eg'.
'making a comeback' says the letters should be written backwards.
'eg' in reverse letter order is 'ge'.
(Other definitions for forge that I've seen before include "Blacksmith's workshop", "1 across", "Smith's workshop", "Ironworks", "Form by heating and hammering".)