The World No 3 made his colourful intervention in the independence debate in a wide-ranging interview.
But although the Dunblane-raised sportsman did not indicate which way he will vote in next year’s referendum, he made clear that his head would rule his heart.
“You need to figure out what’s best for the country and then come to an opinion,” he said. “I want to read more about the issue. I don’t think you should judge the thing on emotion, but on what is best economically for Scotland. You don’t want to come to a snap decision and then see the country go tits up.”
The player also revealed that he made his breakthrough US Open Grand Slam triumph in September only after giving himself a stern pep talk in the toilets after losing a two-set lead in his clash with Novak Djokovic. He said: “I stood in front of the mirror with sweat dripping and I knew I had to change what was going on inside. So I started talking. Out loud: ‘You are not losing this match.’ I said to myself: ‘You are not losing this match.
“I started out a little tentative, but my voice got louder: ‘You are not going to let this one slip away…’ At first, it felt weird, but I felt something change inside. I was surprised by my response. I knew I could win.”