Concerned with journalist accepting team is unbalanced (3-5)
I believe the answer is:
one-sided
'unbalanced' is the definition.
(I've seen this before)
'concerned with journalist accepting team' is the wordplay.
'concerned with' becomes 'on' (I've seen this in other clues).
'journalist' becomes 'ed' (short for editor).
'accepting' indicates putting letters inside.
'team' becomes 'side' (I've seen this before).
'ed' enclosing 'side' is 'esided'.
'on'+'esided'='ONE-SIDED'
'is' is the link.
(Other definitions for one-sided that I've seen before include "Unbalanced" , "Unfair, unequal" , "Biased, favouring one part over another" , "Unfairly biased" , "Unilateral" .)