The move, announced ahead of the 2017 WGC-Bridgestone Invitational, was initially expected to be a short-term thing whilst McIlroy weighed up potential replacements for Fitzgerald.

“We've been inundated with people wanting to have a chance to carry the bag,” said McIlroy prior to the 2017 US PGA. “But I can't really think about that until next week, until I have a week off, and then I can reassess how these couple of weeks have gone with Harry on the bag.”

In the end, he opted to stick with novice caddie Diamond.

A talented golfer in his own right – his handicap is reportedly in ‘plus’ numbers – Diamond played junior golf with Rory at their home club, Holywood, in Northern Ireland.

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They struck up a firm friendship, with Diamond invited to caddie for a 16-year-old McIlroy when he played in the 2005 Irish Open. He was on the bag again for the Par-3 Tournament at the 2011 Masters, as well as for the 2014 Alfred Dunhill Links Championship.

They are such close friends that Diamond was on best man duty when McIlroy married Erica Stoll in 2017.

Despite having been good enough to potentially have a crack at the pro game – he won the 2012 West of Ireland Championship, reached the final of the 2011 North of Ireland Championship, and represented Ireland at international level – Diamond opted to stay amateur and focus on his business interests.

He had been part of a family business which owns a chain of hotels, pubs and restaurants in Belfast and Bangor… that was until the opportunity arose join his old friend Rory on tour.

The duo scored their first victory together at theArnold Palmer Invitational at Bay Hill in March  of this year.