Digressions used by top class teams? (6)
I believe the answer is:
asides
'digressions' is the definition.
('aside' can be a synonym of 'digression')
'by top class teams?' is the wordplay.
'by' means one lot of letters go next to another.
'top class' becomes 'a' (top grade).
'teams?' becomes 'sides' (eg football sides).
'a' put next to 'sides' is 'ASIDES'.
'used' acts as a link.
(Other definitions for asides that I've seen before include "They're not heard by everybody" , "Words spoken so that certain people won't hear" , "Stage whisper" , "Words spoken on stage" , "Stage-whispers" .)