Choose to turn pro (2,3)
I believe the answer is:
go for
'choose' is the definition.
(to go for something is to choose it)
'turn pro' is the wordplay.
'turn' becomes 'go' (a person's move in a board game).
'pro' becomes 'for' (I've seen this in another clue).
'go'+'for'='GO FOR'
'to' is the link.
(Other definitions for go for that I've seen before include "Choose" , "Attack (someone), decide on (an option)" .)