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' says to take the initial letters.
'in league' becomes 'allied' (I've seen this before).
The initial letter of 'team' is 't'.
't'+'allied'='TALLIED'
'as' acts as a link.
(Other definitions for tallied that I've seen before include "Agreed, corresponded" , "Matched" , "Reckoned debt or score" , "Agreed; calculated" , "Corresponded - kept score" .)