Rory McIlroy and the Big Brother He Never Had

It’s no secret that Rory McIlroy likes to chat. It’s one of the things that makes him a magnet for people who like him, and a lightning rod for those who do not. He makes bold statements, he changes his mind, he shares deeply personal anecdotes. He cracks jokes, he needles his critics, he says things he’d like to have back. He has the Irish gift of gab.

His caddie and best friend, Harry Diamond, could scarcely be more different.

Diamond almost never grants interviews. He’s done only a couple in the nine years he’s been on McIlroy’s bag, never uttering more than a few words on the rare occasion he grants one. He embodies the cliche about caddies that they have only two requirements: Keep up and shut up.

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But this year’s Masters represents a triumphant return for Diamond as much as it does for McIlroy. For a long time, Diamond had to listen to criticism that he was the reason his boss and good friend wasn’t winning majors, that McIlroy needed to fire him and hire someone with more experience, more of a willingness to stand up to McIlroy in key moments. What was supposed to be a temporary partnership after McIlroy fired JP Fitzgerald in 2017 turned into a permanent one when McIlroy decided he felt at peace with his close friend on the bag. Instead of blaming McIlroy for his shortcomings, much of the golf world (including the media) pointed a finger at Diamond.

Diamond never cared to defend himself.

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What most of his critics failed to grasp is that no one was going to stand up to McIlroy on the golf course. Even Steve Williams would have been overruled. McIlroy is too stubborn to be talked out of anything he believes he can do. If that’s the case, why not go with good vibes? Diamond never got credit for any of McIlroy’s great golf; he only shouldered the blame when things went bad. That fact alone seemed pretty unfair.

But in the 2025 Masters, it was Diamond who got McIlroy to reset his brain after he missed a putt in regulation on 18 that would have won him the green jacket. On the ride back to the 18th tee for the playoff, Diamond reminded him of one simple fact: Hey pal, we would have taken a playoff at the start of the week.

You can tell how important their relationship is to McIlroy the few times he’s answered questions about Diamond and his importance in McIlroy’s life. He got choked up the night of the Masters when asked about Diamond, the only time it happened during his victory press conference. And McIlroy got choked up again in the recent documentary when he talked about how Diamond was the first person he looked at when he made the winning putt.  

Most people know about the history of their friendship. They met on the putting green at Holywood Golf Club when they were just kids. Diamond was two years older, but he befriended McIlroy anyway. They spent years playing golf together and were the best men in each other’s weddings. But I wondered why, in particular, questions about Diamond made McIlroy so emotional over the last year. So I asked him during his press conference on Tuesday.

“Being an only child, I think he’s the big brother I never had,” McIlroy said. "I think that's what makes it so special. Harry's got a little brother and a big sister, so he had that. But I always felt like Harry was my big brother. I think that's why, when I talk about it, that’s why it makes me emotional."