Phil Mickelson has revealed he is to return from his self-imposed hiatus from golf, and do so in this week’s opening event of the Saudi-backed LIV Golf Invitational Series.

The 51-year-old has not played since controversial comments about the breakaway series and the PGA Tour, including describing the Saudis in unflattering terms, were published in February.

Tiger Woods, however, turned down a “mind-blowingly enormous” deal according to Greg Norman, chief executive and commissioner of LIV Golf.

“We’re talking about high nine digits,” Norman said.

It is not known how much Mickelson will be paid to play in the controversial tournament.

Tweet from @BrentleyGC

“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,” Mickelson said in a statement posted on Twitter.

“I needed to start prioritising the people that I love the most and work on becoming a better version of myself.

“I have spent this time with [his wife] Amy and loved ones. I have been engaged and intentional in continued therapy and feel healthy and much more at peace. I realise I still have a long way to go, but I am embracing the work ahead.”

Mickelson went to explain some of the reasons why he decided to back the LIV series.

“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,” he said.

“I also love the progressive format and think it will be exciting for fans. Just as importantly, it will provide balance, allowing me to focus on a healthier approach to life on and off the course. I am incredibly grateful for what this game and the PGA Tour has given me.

“I would like to think that I have given back as well but now I am excited about this new opportunity.”

Tweet from @PhilMickelson

Besides the $US4 million ($5.5 million) for the winner of each event Mickelson is likely to have received a huge signing-on fee. Dustin Johnson, hitherto the rebel tour’s biggest capture, received a reported $US150 million ($A208 million).

“I intend to play the majors,” Mickelson said.

The PGA Tour has threatened a ban of any players that compete in a LIV Golf event.

The next major is the US Open on June 16-19. While Mickelson is an exempt player and filed an entry to compete, the Unites States Golf Association reserves the right to review any player’s situation on a case-by-case basis.

Among the other golfers already confirmed for the 48-player LIV event being held June 9-11 at Centurion Club are former world No.1s Lee Westwood and Martin Kaymer as well as 2017 Masters champion Sergio Garcia and 2010 British Open winner Louis Oosthuiszen.