Place on a team for reserve
I believe the answer is:
set aside
'reserve' is the definition.
('set aside' can be a synonym of 'reserve')
'place on a team' is the wordplay.
'place' becomes 'set' ('set' can be a synonym of 'place'**).
'on' means one lot of letters go next to another.
'team' becomes 'side' (I've seen this before).
'set'+'a'+'side'='SET-ASIDE'
'for' is the link.
(Other definitions for set aside that I've seen before include "Farm land taken out of production" , "Reserve(d) in advance" , "The policy of taking land out of production to reduce crop surplus" , "Lay by" , "Save or discard" .)