Stand-in team collapse (7)
I believe the answer is:
subside
'collapse' is the definition.
(I've seen this before)
'stand-in team' is the wordplay.
'stand in' becomes 'sub' ('sub' can be a synonym of 'stand in').
'team' becomes 'side' (I've seen this before**).
'sub'+'side'='SUBSIDE'
(Other definitions for subside that I've seen before include "Sink, settle" , "Abate" , "Collapse" , "(Flood) go down" , "Sink to a lower level" .)