Criticism towards Rory McIlroy's caddie after U.S. Open loss doesn't sit well with Shane Lowry: 'It makes my blood boil'

After Rory McIlroy’s stunning defeat at the U.S. Open last month, several media members and hundreds of fans criticized Harry Diamond, McIlroy’s caddie, for a lack of communication down the stretch.

For example, Smylie Kaufman had this to say during an appearance on Golf’s Subpar Podcast: “I felt like (caddie) Harry Diamond really should have stepped in on the 15th hole. He did not have the right club in his hands. And I felt like Rory could have taken control of the championship on 15 if he just hits it in the middle of the green. And he hit a good shot. But it just was the wrong club.”

Hank Haney commented on the same situation via social media: “If Steve Williams was Rory’s caddie I can promise you he would have never hit a perfect flighted 7-iron that rolled over the green on 15 into a terrible lie.”

McIlroy came to his looper’s defense before last week’s Genesis Scottish Open, where he’d go on to finish T-4, and now it’s another Irishman sticking up for Diamond.

“It makes my blood boil, to be honest,” Lowry told BBC Sport NI at Royal Troon before the 152nd Open Championship. “They don’t see how hard Harry works and how good he is for Rory. Just because he’s not standing in the middle of the tee box like other caddies who want to be seen and heard doesn’t mean that his voice isn’t heard by Rory.”

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It’d be tough to find another Tour player who spends more time with McIlroy and Diamond than Lowry. They have been friends for years, play practice rounds together before major championships, have been Ryder Cup teammates twice (2021, 2023) and represented Ireland at the 2021 Olympics. Plus, they won the Zurich Classic as a team earlier this season.

If anyone knows how well McIlroy and Diamond work together, it’s Lowry.

For the opening round of The Open, world No. 33 Lowry tees off Thursday at 9:59 a.m. ET alongside Cameron Smith and Matt Fitzpatrick. Rory McIlroy is grouped with Max Homa and Tyrrell Hatton at 5:09 a.m.