Team leader in league, as agreed (7)
I believe the answer is:
tallied
'agreed' is the definition.
('tally' can be a synonym of 'agree')
'team leader in league' is the wordplay.
'leader' suggests taking the first letters.
'in league' becomes 'allied' (I've seen this before).
The initial letter of 'team' is 't'.
't'+'allied'='TALLIED'
'as' is the link.
(Other definitions for tallied that I've seen before include "Agreed, corresponded" , "Matched" , "Reckoned debt or score" , "Agreed; calculated" , "Corresponded - kept score" .)