Matthew Wolff will play in the event alongside Carlos Ortiz of Mexico and world number two amateur Eugenio Chacarra.
The three players will join a field that includes Phil Mickelson, Dustin Johnson, Bryson DeChambeau as well as English duo Ian Poulter and Lee Westwood.
The LIV Golf Invitational Portland event at Pumpkin Ridge will take place from June 30 to July 2.
The line-up will have nine of the previous 21 Grand Slam winners and four former world number ones.
"Our impressive roster of LIV golfers continues to grow with incredible young talent and international stars," said Greg Norman, CEO and Commissioner of LIV Golf.
"Matthew Wolff and Eugenio Chacarra have both made a name for themselves as two of golf's most promising talents, exhibiting impressive success at an early age.
"I'm eager to watch them play alongside Carlos Ortiz, one of Mexico's most consistent pros who along with many of our other golfers represents LIV Golf's continued commitment to growing the game on a global scale.
"LIV Golf is providing new opportunities for the best players in the world to compete, and our field in Portland reflects that. We can't wait to kick off our first U.S. event with these incredible golfers."