Teams take action about one minor concern (4,5)
I believe the answer is:
side issue
'minor concern' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.
'teams take action about one' is the wordplay.
'teams' becomes 'sides' (eg football sides).
'take action' becomes 'sue' (as in suing somebody in court).
'about' indicates putting letters inside.
'one' becomes 'i' (Roman numeral).
'sides'+'sue'='sidessue'
'sidessue' going around 'i' is 'SIDE ISSUE'.
Can you help me to learn more?
(Other definitions for side issue that I've seen before include "Ancillary consideration" , "It's not an important matter" , "That's not so important" , "Incidental topic" , "minor affair" .)