Relegated team getting stuffed (9)
I believe the answer is:
sidelined
'relegated' is the definition.
'team getting stuffed' is the wordplay.
'team' becomes 'side' (I've seen this before).
'getting' means one lot of letters go next to another.
'stuffed' becomes 'lined' (both can mean filled with).
'side'+'lined'='SIDELINED'
(Other definitions for sidelined that I've seen before include "Removed from active participation" , "Confined to the periphery" , "Prevented from participating" , "Kept to the periphery" , "kicked downstairs" .)