Not going for rest? Describes the snooker player who can't pot a ball! (7,1,5)

'not going' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.

'rest? describes the snooker player who can't pot a ball' is the wordplay.
I cannot really understand how this works, but
'rest?' could be 'break' (resting is a kind of breaking) and 'break' is present in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found within the answer.
'a' is within the answer.
'ball' could be 'o' (letter resembling a ball) and 'o' is present in the answer.
This may be the basis of the clue (or it may be nonsense).

'for' is the link.

Can you help me to learn more?