DeChambeau's former coach Mike Schy has accused the U.S Open champion of reneging on a promise to underwrite the cost of a junior tour in California - named after DeChambeau's late father Jon.

In response, DeChambeau told another publication "it's a complete and utter lie", labelled Schy a "disgruntled employee" and he and his agent have accused Schy of trying to "extort" $US2 million ($A3 million) after DeChambeau's second U.S Open triumph at Pinehurst last month.

Schy had worked with DeChambeau since the age of 11 and was often referred to by the world No.9 as his second father.

Bryson Dechambeau and former coach Mike Schy at the 2016 RBC Heritage on the PGA Tour. PHOTO: Getty Images.

"He said I'm his second dad, right?" Schy said in the article. "He treats me just like his real dad. He treated his dad like s***."

Asked in his pre-Open press conference if his relationship with Schy had irretrievably broken down, DeChambeau said: "Look, it's an unfortunate situation.

"I've loved that man for all of my life and it's a private matter that went public, unfortunately. We tried to figure it out and make sense for everyone, and it just didn't come out that way.

"I've said all I've said in the Golfweek article, and to be honest, I'm moving on and looking forward to a great tournament this week. Not going to have any of that in the rear-view mirror.

"History is history, and things will work themselves out. They always do."

DeChambeau has been in brilliant form in the majors this season, finishing sixth in the Masters - where he broke his personal par of 67 at Augusta National by two shots in the first round - and runner-up in the U.S PGA Championship behind a record-breaking Xander Schauffele.

His record in the Open Championship is not as impressive however, with his sole top 10 in six previous appearances coming at St Andrews in 2022.

The 30-year-old is also competing at Troon for the first time as he only turned professional three months before the Ayrshire venue last staged the Open in 2016.

"It's a tough golf course," DeChambeau said. "That back nine has some teeth and you've got to drive it straight, you've got to control your golf ball.

"Controlling that golf ball underneath the wind is going to be super key this week. I hit the golf ball really high, so it's always been a bit of an issue. I've got to keep the ball under the wind a bit more, keep a lower flight."