Brooks Koepka has become the latest high-profile player to trade the PGA Tour for the LIV Golf Invitational Series.
The likes of Phil Mickelson, Dustin Johnson and Sergio Garcia were among the early joiners of the Saudi Arabia-backed breakaway competition, which started earlier in June in London.
Bryson DeChambeau and Patrick Reed followed suit as they announced their intention to play in LIV Golf tournaments, with all participants aware they would be indefinitely suspended from the PGA Tour.
The breakaway golfers were still allowed to participate at the U.S. Open, where Koepka said he was "tired of conversations" about the new circuit and asserted LIV Golf debates were "throwing a black cloud" over the third major of 2022.
Four-time major winner Koepka, who finished 55th at Brookline, then removed all references to the PGA Tour from his social media profiles as expectations grew that he would trade allegiances.
The world number 19's move was subsequently confirmed on Wednesday and he will feature in the second event at Pumpkin Ridge in Portland, Oregon, which starts on July 3.
"There's no understating the impact that Brooks Koepka has had on the game of golf in the last five years," LIV Golf chief executive Greg Norman said.
"He carries a championship pedigree and record of success as one of the most elite players in the world
"The addition of Brooks is yet another example of the incredible fields LIV Golf is assembling as we build momentum in our first season and look towards the future."
Six further tournaments will follow for LIV Golf this season, with the total prize fund for the eight competitions £200million, with Charl Schwartzel collecting £3.9m when he won the opening 54-hole competition.
Uncertainty remains as to what the breakaway league means for further participation at the majors, with USGA chief executive Mike Whan admitting he could foresee a day where players may be banned.
Koepka becomes the ninth major champion to defect to LIV Golf, along with Garcia, Johnson, Mickelson, Martin Kaymer, Graeme McDowell, Louis Oosthuizen, Schwartzel and DeChambeau.
World ranking points remain unavailable for LIV Golf events, but Norman – himself a two-time major champion – has said an application for that to change has been submitted.