Phil Mickelson is convinced the LIV Golf Invitational Series is "here to stay" and the PGA Tour's dominance has come to an end.
The 52-year-old is one of several high-profile players to move from the PGA Tour to the new controversial Saudi-backed LIV Golf, including Bryson DeChambeau and Open champion Cameron Smith.
The PGA Tour has been rocked by LIV Golf's emergence and since introduced numerous changes to retain players, such as increasing purses and encouraging its biggest names to play together more often. It has also suspended defectors from its tournaments.
But Mickelson believes the PGA Tour will have to come to terms with losing players to LIV Golf, telling reporters: "The PGA Tour, for the last 20 or 30 years have had all the best players in the world.
"That will never be the case again. LIV Golf is here to stay."
The bitter dispute led to some defectors suing their former tour, but Mickelson believes cooperation between the two rival tours would be beneficial for the sport.
"The best solution is for us to come together," added Mickelson after a two-under-par opening round of the ongoing LIV Golf tournament in Chicago.
"I think that the world of professional golf has a need for the old historical 'history of the game' product that the PGA Tour provides. I think that LIV provides a really cool, updated feel that is attracting a lot younger crowds.
"Both are good for the game of golf and the inclusion of LIV Golf in the ecosystem of the golf world is necessary. As soon as that happens, we all start working together. It's going to be a really positive thing for everyone."