Northern Ireland’s Rory McIlroy is amongst the star-studded US Open field battling it out for glory at Shinnecock Hills – but a major championship isn’t the only thing on the line with a whopping prize money purse also available.

McIlroy currently sits $5million adrift of leader Tiger Woods on the all-time PGA Tour money charts and a healthy cheque in New York would help him further close the gap – and add to his already staggering $115.97million tally.

The 37-year-old made a solid start in testing conditions during Thursday’s opening round, registering a one-under par 69 – the highlight was an eagle at the fifth.

McIlroy won his sole US Open crown – and the first of his six majors to date – at Congressional Country Club in 2011, finishing eight shots clear of Jason Day.

placeholder image — Rory McIlroy is in action at the US Open this weekend. (Photo by Kate McShane/Getty Images)

The Holywood native collected a winner’s purse of $1.44million for that success, but that pales in comparison to what is on offer for the 2026 champion.

USGA CEO Mike Whan announced earlier this week that $22.5million will be up for grabs across the field – an increase of $1million from a year ago and the fifth time in six years the pot has been boosted.

It means the US Open stands alongside the Masters as golf’s most lucrative major tournament with only the Players Championship ($25million) boasting a bigger purse across the calendar.

This weekend’s winner will earn a record $4.5million – the same amount McIlroy banked for claiming his second Masters at Augusta in April.

“We believe, and it's fair if you want to disagree with it, we believe we're the best championship in the game, and we want a lot of aspects to be the best championship in the game,” said Whan according to Golf Digest. “Where we go, how we treat the players, how we pay out, how we're televised, and we're proud of the fact there's more network hours on the U.S. Open than any other major championship.

“Yeah, some of that's just personal pride. We want to be big, we want to be the best, we want to make sure it's life-changing in multiple ways.

“We also are not in a race, we're not chasing. I don't know if that answers your question, but we're proud of where we are.

"I couldn't tell you and until I get some truth serum in here how much farther we go in the years to come, but we think it's a measure of how we feel about our championship. It needs to be significant and stand out. We think 22.5 does.”

McIlroy voiced his concerns earlier this week that a “false economy” created by the threat of LIV Golf may now be putting some well-established events at risk.

The world number two felt people had lost sight of how good the PGA Tour was before it too had a huge cash injection.

“It was a pretty good structure, and everything sort of worked pretty well,” he said. “LIV created this false economy where we had to up prize funds and had to cut fields and try to support the top players.

“I think (it) needed to happen because that was the only way to retain talent at the time, but now that LIV looks like it’s less of a threat, I think, as I said, the old ways of the PGA Tour weren’t actually that bad.

“An event like last week, the Canadian Open, potentially going to one of these Track 2s. Track 2 is a glorified Korn Ferry (second-tier) event. I don’t think the Canadian Open should be one of those.

“I just think there’s going to be certain events that might lose their stature if a sponsor doesn’t pony up 30 million dollars, so that’s the tough thing.”