Change made by video assistant referee? Yes, initially (4)
I believe the answer is:
vary
'change' is the definition.
(I know that change can be written as vary)
'video assistant referee? yes initially' is the wordplay.
'initially' says to take the initial letters.
The first letters of 'video assistant referee yes' is 'VARY'.
'made by' acts as a link.
(Other definitions for vary that I've seen before include "Change, amend" , "Make a change in" , "Change, modify" , "Undergo change" , "Be dissimilar" .)