He has real potential! (4)
I believe the answer is:
earl
'he' is the definition.
'real potential' is the wordplay.
'potential' is an anagram indicator (another potential order of the letters).
'real' is an anagram of 'EARL'.
'has' is the link.
(Other definitions for earl that I've seen before include "UK nobleman ranking between marquess and viscount" , "Peer of the realm" , "A real titled lord" , "A real sort of lord" , "Rank below marquess" .)