Six-time major champion Phil Mickelson will play at this week’s opening event of the LIV Golf Invitational Series after a four-month break from the game.
The American has not played since controversial comments about the Saudi-funded breakaway series were published by his biographer in February.
Mickelson completes a 48-strong field in the $25m (£20m) Greg Norman-led event at Centurion Club in St Albans.
The 51-year-old had sought a release from the PGA Tour to play in the event.
However, the PGA Tour has said players taking part in the event could face sanctions.
In a statement on Twitter, Mickelson said taking time away from the sport has been “humbling”.
Mickelson lost multiple sponsors and saw his reputation tarnished after he criticised the Saudi regime, yet sought to use involvement with the series to gain leverage over the PGA Tour.
He subsequently missed the Masters for the first time in 28 years as well as last month’s US PGA Championship, where he would have been defending champion.
“First and foremost, I want to again apologise to the many people I offended and hurt with my comments a few months ago,” he said.
“I have made mistakes in my career in some of the things I have said and done. Taking time away and self-reflecting has been very humbling.”
Having missed the past two majors, Mickleson says he intends to play at the US Open at Brookline, Massachusetts, later in June.
He has not spoken to PGA Tour commissioner Jay Monahan but intends to continue playing in the biggest tournaments and said he will not resign his membership of the main tour in the United States.
He added: “I am thrilled to begin with LIV golf and I appreciate everyone involved. I also intend to play the majors.
“I fully realise and respect some may disagree with this decision and have strong opinions and I empathise with that.
“I am ready to come back to play the game I love but after 32 years this new path is a fresh start, one that is exciting for me at this stage of my career and is clearly transformative, not just for myself, but ideally for the game and my peers.”
In an interview with American sports magazine Sports Illustrated, Mickelson also denied suggestions that his involvement with the LIV series is due to financial difficulties caused by gambling losses.
“My gambling got to a point of being reckless and embarrassing,” he said.
“I had to address it. And I’ve been addressing it for a number of years. And for hundreds of hours of therapy. I feel good where I’m at there. My family and I are and have been financially secure for some time.”
Asked specifically about Saudi Arabia’s human rights record and the murder of journalist Jamal Khashoggi, Mickelson added: “I certainly do not condone human rights violations.
“And addressing what happened to Jamal Khashoggi is awful. But I have seen the good that the game of golf has done throughout history. And I really believe that LIV can be good for the game of golf as well.”
Mickelson joins players such as two-time major winner Dustin Johnson – who has reportedly signed a deal worth $150m to play in the series – England’s former world number one Lee Westwood, Ian Poulter and Spaniard Sergio Garcia.
In an interview with the Washington Post, Norman said 15-time major winner Tiger Woods had been offered a “mind-blowingly enormous” deal to take part in the series.
“We’re talking about high nine digits,” he added.
Norman has shelved plans to run the series as a league format, instead each event will run as an invitational tournament until 2024.
“Phil Mickelson is unequivocally one of the greatest golfers of this generation,” said Norman. “His contributions to the sport and connection to fans around the globe cannot be overstated and we are grateful to have him.
“He strengthens an exciting field for London where we’re proud to launch a new era for golf.”
This initial $255m (£202m) invitational series will feature six more regular season tournaments in 2022 – four in the United States, one in Thailand and one in Saudi Arabia – each having the same $25m (£20m) prize fund, meaning every leg of the series is more lucrative than the richest tournament on the PGA Tour.
The events will feature a team and individual competition, with 12 captains selecting three players in a draft-style format. Each day, the teams of four will tee off at the same time on different holes in what is termed a ‘shotgun start’.
Each event’s individual winner will take home $4m – by way of comparison, the PGA Tour’s flagship event, the Players Championship, earned Cam Smith $3.6m for his victory in March, while Collin Morikawa won $2m for his Open Championship victory in 2021.
The eighth and final event, at Trump National Doral in Miami in October, will be a $50m ‘Team Championship’ matchplay knockout tournament featuring 12 teams. The winning team will receive $16m, with each of the four players earning a 25% cut.
Iain Carter, BBC golf correspondent
Mickelson’s comments, heavily critical of Saudi Arabia and the PGA Tour, were made public in February and spectacularly derailed the LIV Golf project.
The then reigning US PGA Champion was the intended face of a new Formula 1-style golf super league. Instead, he disappeared from public life, admitting he needed to take steps to become a better person.
This was regarded as a huge downfall for one of golf’s most popular figures. But despite graphically branding the Saudis as “scary” he is making his return at the first of their events. He is likely to be receiving big appearance money that will run into millions of dollars. Rumours in the US have suggested he has signed a $200m deal.
Mickelson says he will continue to play majors but it is significant that he makes no mention of the PGA Tour in a future that now involves, as originally intended, being the LIV project’s most illustrious poster boy.