This is very similar to the last post (also from Balboa) with a tee shot hitting my golf bag. Today, I was chipping on 18, and my chip came up short. It was clearly going to roll back to me, and there was a very good chance that it would hit my putter, which was sitting beside the green. So I moved my putter out of the way while the ball was in motion.
Rule #11.3 says that you may not move anything that might affect the ball, while the ball is in motion. But moving a club (or any other equipment) is a specific exception to this rule. So you can move a club out of the way of the ball. By the same rule, you can move a ball on the putting green that the ball in motion may hit (thus avoiding breaking rule #11.1, which is two strokes for hitting another ball on the putting green).