Surface is unacceptable to team (7)
I believe the answer is:
outside
'surface' is the definition.
(I know that outside is a type of surface)
'unacceptable to team' is the wordplay.
'unacceptable' becomes 'out' (out can mean incorrect or inappropriate).
'to team' becomes 'side' (both can mean a sports team).
'out'+'side'='OUTSIDE'
'is' is the link.
(Other definitions for outside that I've seen before include "Tedious (anag)" , "Exterior" , "Al fresco" , "Not indoors" , "External surface" .)