In time, half the team become friendly (5)
I believe the answer is:
matey
'friendly' is the definition.
(similar in meaning)
'in time half the team' is the wordplay.
'in' is an insertion indicator.
'time' becomes 'may' (I've seen this before).
'half the' suggests halving the letters.
'team' cut in half is 'te'.
'may' going around 'te' is 'MATEY'.
'become' acts as a link.
(Other definitions for matey that I've seen before include "Pally" , "Pirate's chum (colloq.)" , "Friendly, sociable" , "Sunshine" , "Close chum (slang)" .)