Extras the opener Boycott gets? That's right! (4)
I believe the answer is:
byes
'extras' is the definition.
(I've seen this before)
'opener boycott gets? that's right' is the wordplay.
'opener' suggests taking the first letters.
'gets?' means one lot of letters go next to another.
'that's right' becomes 'yes' (right can mean yes or okay).
The first letter of 'boycott' is 'b'.
'b'+'yes'='BYES'
'the' acts as a link.
(Other definitions for byes that I've seen before include "Greedy person; seabird" , "Wicketkeeper's concession" , "Cricketing extras" , "Runs wicketkeeper concedes" , "Scores" .)