Kevin Na has announced his resignation from the PGA Tour ahead of his participation in the LIV Golf Invitational Series.

Na, who is a five-time winner on the PGA Tour, posted on social media on Saturday his reasons for resigning, suggesting it was due to the Tour's attitude towards players competing in rival events.

A Saudi-backed rival to the PGA Tour had been rumoured for years before the launching of LIV Golf was recently confirmed.

Greg Norman, a two-time Open champion and LIV Golf's CEO, described it as the arrival of "free agency" in golf, with leading players skipping PGA Tour events to play in the new series.

However, the Tour has previously suggested it would ban players who joined the breakaway.

Na, who is the world number 33, was among 13 players from the PGA Tour listed as part of the field for the first LIV Golf event in London next week, along with the likes of Dustin Johnson, Lee Westwood and Sergio Garcia.

Na posted on Twitter: "For 19 years I have played on the PGA Tour and loved every minute of it. I appreciate the platform the Tour has provided me to play the game I love and for the opportunities that come with it.

"Recent developments in the professional golf world have given me a chance to reconsider my options. I would like the freedom to play wherever I want and exercising my right as a free agent gives me that opportunity.

"However, to remain a PGA Tour player, I must give up my right to make these choices about my career. If I exercise my right to choose where and when I play golf, then I cannot remain a PGA Tour player without facing disciplinary proceedings and legal action from the PGA Tour.

"I am sad to share that I have chosen to resign from the PGA Tour. This has not been an easy decision and not one taken lightly. I hope the current policies change and I'll be able to play on the PGA Tour again.

"I am thrilled to begin the next chapter in my career, starting next week at the inaugural LIV Invitational Series event in London. I hope you'll continue to support me."

The 38-year-old's last Tour win came in January 2021 at the Sony Open in Hawaii.

Jim Furyk rolled back the years with a hole-in-one at the Sony Open to finish the opening round in Hawaii one shot behind leader and defending champion Kevin Na.

The 51-year-old, who has 17 PGA Tour victories to his name, sunk the perfect shot on the par-three 17th on his way to finishing eight under on Thursday.

Furyk was hampered by a slow start at Wai'alae Country Club with a bogey on the opening hole, though that proved to be the American's only dropped shot in a round of 62.

That makes Furyk the oldest player to shoot 62 or better on the PGA Tour since 1983 as he looks to win the tournament for a second time, 26 years on from his previous triumph.

"I'm trying to get ready for this year. I want to be competitive this week," said Furyk, who made the sixth hole-in-one of his career and first since 2011.

"I want to compete and put myself in position, in the hunt, and also want to get a feel for where my game is and what I want to work on for the year."

Furyk will resume day two level with compatriot Russell Henley and a stroke behind blemish-free Na, who is aiming to defend the crown he won last year.

Na was on course for a sub-60 round, but three good birdie chances passed him by and he now has seven challengers within two shots of his lead.

The South Korean settled for 61 to tie his career-low round on the PGA Tour. He leads the way for the most rounds-of-62 or better since such data was first recorded in 1983 (10).

Na, Furyk and Henley are three of six past Sony Open winners in the top 10 after day one, along with Matt Kuchar, Patton Kizzire (both six under) and Ryan Palmer (seven under).

Elsewhere, Cameron Smith could not build on his record-breaking win at last week's Sentry Tournament of Champions as a couple of bogeys left him three-under par in a tie for 40th.