Buddy bringing excitement to team (8)
I believe the answer is:
sidekick
'buddy' is the definition.
('sidekick' can be a synonym of 'buddy')
'excitement to team' is the wordplay.
'excitement' becomes 'kick' (kick is a kind of excitement).
'to' is a charade indicator (letters next to each other) (I've seen this in other clues).
'team' becomes 'side' (I've seen this before).
'kick' after 'side' is 'SIDEKICK'.
'bringing' acts as a link.
(Other definitions for sidekick that I've seen before include "Fellow adventurer - partner or deputy" , "Junior associate" , "Acolyte" , "Close friend" , "personal assistant" .)