Jack Nicklaus has pledged that his Memorial Tournament will fall in line with the PGA Tour if it bans or suspends players for competing in the LIV Golf Invitational Series.
The PGA Tour has refused to grant the likes of Phil Mickelson and Lee Westwood the required releases to contest the first event at Centurion Club next week, with LIV Golf CEO Greg Norman vowing to "defend, reimburse and represent" any players sanctioned if they play regardless.
Portrush's Graeme McDowell and two-time Major champion Dustin Johnson are among the names included for the opening event. There had been recent reports that McDowell was reconsidering his position on the series.
LIV Golf announces field for first event in London next week. Among the big names: Dustin Johnson, Sergio Garcia, Ian Poulter, Kevin Na, Lee Westwood, Louis Oosthuizen, Martin Kaymer, Charl Schwartzel, Graeme McDowell, Talor Gooch. Not listed: Phil Mickelson. pic.twitter.com/AUlcFD5oS4
— Jason Sobel (@JasonSobelTAN) June 1, 2022
Former world number Johnson one will headline the new competition's inaugural event at the Centurion Club from June 9-11, just four months after committing himself to the PGA Tour.
Johnson, currently world number 13, is the biggest name so far to announce he will take part and risks sanctions by the PGA, which has not granted members permission to play.
The 37-year-old American's agent David Winkle said in a statement: "Dustin has been contemplating the opportunity off-and-on for the past couple of years.
"Ultimately, he decided it was in his and his family's best interest to pursue it. Dustin has never had any issue with the PGA Tour and is grateful for all it has given him, but in the end, felt this was too compelling to pass up."
The winner at the Centurion Club will receive #3million out of a total prize fund of #20m and Johnson will join the likes of Louis Oosthuizen, Branden Grace, Lee Westwood, Ian Poulter, Sergio Garcia, Kevin Na and Martin Kaymer in a 48-man field.
Johnson had been scheduled to play in the Canadian Open, which also starts next week, but will now line up in the first of eight new worldwide LIV Series events to be held from June to October.
Canadian Open organisers announced on Twitter: "Together with our partners at RBC, we are disappointed to learn at this late stage that Dustin Johnson has made the decision to play the LIV Golf Event. As a past RBC Canadian Open champion, Canadian golf fans were looking forward to DJ's return this year."
LIV Golf chief executive Greg Norman has been heavily criticised for heading up the breakaway tour, with its Saudi investors accused of "sportswashing" their country's poor human rights record.
But Norman said: "Free agency has finally come to golf. This is an opportunity to start a movement that will change the course of history by bringing new and open competition to the sport we all love.

"The desire shown by the players to participate in LIV Golf demonstrates their emphatic belief in our model and confidence in what we're building for the future."
The LIV Golf Series will adopt a new format in a bid to make the sport more exciting for fans, with 12 teams of four players contesting in each three-round event to determine team and individual winners.
Asked if competing in the LIV events would place invitations to his tournament at risk, Nicklaus said in a pre-event press conference: "The PGA Tour will answer that. I don't think that's my question, frankly.
"We live by the rules of whatever the PGA Tour is. That's what we do."
The Memorial Tournament is an invitational, referred to by the PGA Tour as an "elevated event" along with the Arnold Palmer Invitational and the Genesis Invitational. They all have purses of $9.5million with 120-man fields.