Players supporting game opponents in media show (8)
I believe the answer is:
newscast
'media show' is the definition.
(news broadcast)
'players supporting game opponents' is the wordplay.
'players' becomes 'cast' (group of actors).
'supporting' means one lot of letters go next to another (in a down clue, some letters go below others).
'game opponents' becomes 'news' (in bridge, players are named after compass points).
'cast' after 'news' is 'NEWSCAST'.
'in' acts as a link.
(Other definitions for newscast that I've seen before include "Broadcast of recent happenings" , "Topical programme" , "Current affairs bulletin" , "TV bulletin" , "Source of information" .)