Los Angeles, United States — World number one Ko Jin-young will miss the defence of her Portland Classic title this week with a wrist injury, but she hopes to return next month in South Korea.

"Jin-young is sitting out the next few weeks under medical advisement for 'an overworked wrist'," said a statement from Ko's management team.

"She hopes to return at the BMW Ladies Championship."

That timetable would mean Ko will also miss defending her title at The Ascendant LPGA Tour event in Texas in two weeks but return for the BMW, where she is also the defending champion, in her homeland from October 20-23.

Victory would put Ko in position to retain her title in the season-ending Tour Championship on November 17-20 at Naples, Florida.

Ko won last year's Portland title by four strokes from compatriot Lee5 Jeong-eun when storms trimmed the event to 54 holes.

This season, Ko won in March in Singapore and has three top-five finishes but she missed the cut in her two most recent events, the Women's British Open and Canadian Open.

After it was played last year at nearby Oregon Golf Club, the Portland Classic returns to long-time home course Columbia Edgewater Country Club.

Portland is the longest-running non-major LPGA stop, having first been played in 1972.

Meanwhile, in response to the challenge of the Saudi-backed LIV Golf Series, top golfers will play more often for richer purses in the 2022-23 US PGA Tour campaign that begins Thursday.

The PGA's final wrap-around season before returning to a calendar-year format in 2024 opens with American Max Homa defending his crown at the Fortinet Championship at Napa, California.

The upstart LIV Series has caused turmoil in the golf world since its June debut, with record purses and financial guarantees luring several top PGA players.

The PGA responded last month by announcing top players would play against each other more often and in more events each season starting in 2022-23.

"We've all made a commitment to get together more often to make the product more compelling," said Rory McIlroy, who last month captured his third FedEx Cup playoff title.

"LIV are going to do what they're going to do. The PGA Tour are just trying to control what they can control and put forward the best product possible.

"Having the top players in the world competing against each other more often is what everyone wants. And I think once we solve for that, a lot of the rest of the stuff sort of takes care of itself."

An expanded bonus program for players based on exposure and minimum payouts of $500,000 for every fully-exempt player were other changes aimed at slowing the tide of defections to LIV Golf.

"Every single member of the PGA Tour is going to benefit from the changes we're going to be making," PGA Tour commissioner Jay Monahan said.

Dustin Johnson, Cameron Smith, Patrick Reed, Bryson DeChambeau, Bubba Watson, Joaquin Niemann, Sergio Garcia and Phil Mickelson were among the players who joined LIV Golf. The PGA Tour gave them indefinite bans.

An anti-trust lawsuit involving LIV Golf and some of its players has a January 2024 court date.

For the season in between, the top stars of the competing tours will meet in next year's four major tournaments — the Masters, the PGA Championship, the US Open and the British Open — as well as The Players Championship.

Top-ranked Masters champion Scottie Scheffler, PGA Championship winner Justin Thomas, Tokyo Olympic winner Xander Schauffele, John Rahm world number two McIlroy and fourth-ranked Patrick Cantlay are among the PGA stars set for the coming campaign.