A golfer is getting ready to putt on the green, with a crowd of people watching in the background.
A golfer readies to putt the ball.
A golfer getting ready to putt is another way of saying a golfer readies to putt the ball.
'A golfer readies to putt the ball' is a rephrasing of 'A golfer is getting ready to putt on the green'.
If a golfer is getting ready to putt on the green, means he is getting ready to putt the ball as it is the ball which is targeted to be put on the hole.