New team companion (4)
I believe the answer is:
mate
'companion' is the definition.
(both can mean a friend)
'new team' is the wordplay.
'new' is an anagram indicator.
'team' anagrammed gives 'MATE'.
(Other definitions for mate that I've seen before include "Friend; chess move" , "tea" , "provides solution to chess problem" , "Marry - friend" , "Freind, companion" .)