A team’s digression (5)
I believe the answer is:
aside
'digression' is the definition.
(synonyms)
'a team's' is the wordplay.
'team' becomes 'side' (both can mean a sports team).
'a'+'side'='ASIDE'
(Other definitions for aside that I've seen before include "secretly" , "In reserve -- confidential remark" , "Quiet words spoken" , "Separately" , "Line spoken to the audience of a play" .)