LOS ANGELES (AFP) — Uncertainty and controversy over a potential merger with LIV Golf's Saudi backers loom over the US PGA Tour as its 2024 season tees off in Hawaii.

The PGA's tournament of champions, now dubbed The Sentry, again will be played at Kapalua, this time in support of wildfire-devastated host Maui following last August's tragedy.

A field of 59 will compete in the $20 million opener with four-time major winner Rory McIlroy the only qualified player skipping the event to begin his 2024 campaign later.

Even as the PGA Tour returns to a calendar-year format, the impact of last June's shock announcement of a framework merger deal with the Saudi Public Investment Fund and DP World Tour lingers over the series.

Reigning Masters champion Jon Rahm of Spain, who won last year's Kapalua crown, will not defend his title, having jumped to LIV last month for rich financial guarantees.

That signals the upstart series can drain top PGA talent ahead of LIV's season openers next month at Mayakoba in Mexico and Las Vegas during Super Bowl week there.

Negotiations between PGA and PIF officials have gone beyond an original December 2023 deadline and still no details have emerged about plans for what a unified PGA-LIV structure would feature even as the rivals plan separate 2024 seasons.

PGA Tour commissioner Jay Monahan, criticized by many players for keeping details of LIV merger talks secret, said in a memo to players on Sunday that LIV talks were "active and productive" and the PGA was working to extend talks into 2024.