Get cracking - play set point! (4,2,2)
I believe the answer is:
step on it
'get cracking' is the definition.
(both can mean to move faster or act quickly)
'play set point' is the wordplay.
'play' indicates anagramming the letters.
'set'+'point'='setpoint'
'setpoint' is an anagram of 'STEP ON IT'.
(Other definitions for step on it that I've seen before include "Move quickly" , "Hurry up, put foot down on pedal" , "Hasten" , "Go for speed" , "Be quick" .)