Article appears after group rehearsed play (3,5)
I believe the answer is:
set piece
'rehearsed play' is the definition.
(I've seen this before)
'article appears after group' is the wordplay.
'article' becomes 'piece' (piece is a kind of article).
'appears after' means one lot of letters go next to another.
'group' becomes 'set' (set is a kind of group).
'piece' put after 'set' is 'SET PIECE'.
(Other definitions for set piece that I've seen before include "Carefully planned manoeuvre" , "Rehearsed move" , "firework display" , "rehearsed play" , "Something arranged for maximum effect" .)