Four-time major winner Rory McIlroy said on Sunday that the Saudi-funded breakaway league hoping to rival the PGA Tour was "dead in the water" after former world number one Dustin Johnson and Bryson DeChambeau committed to the American-based circuit.
Johnson, DeChambeau and several other top-ranked players have turned down the Super Golf League (SGL) project, which is being spearheaded by former world number one Greg Norman.
"Who's left? Who's left to go? I mean, there's no one. It's dead in the water in my opinion. Yeah, I just can't see any reason why anyone would go," McIlroy said.
"No one really knew where Bryson stood. I was really glad to see DJ and Bryson put out those statements this week. We all want to play against the best players in the world and they're certainly two of the best players in the world."
The 32-year-old Northern Irishman also criticised comments made by Phil Mickelson about the breakaway competition in an interview which took place in November but was only just published on the firepitcollective.com website.
The six-time major champion described the Saudi regime as "scary", and added he was only using the threat of the SGL as leverage to prise more concessions out of the U.S.-based PGA Tour.
"I don't want to kick someone while he's down obviously, but I thought they were naive, selfish, egotistical, ignorant," McIlroy said.
"A lot of words to describe that interaction he had. It was just very surprising and disappointing, sad. I'm sure he's sitting at home sort of rethinking his position and where he goes from here."
Players who sign up for the breakaway competition face potential bans from the PGA Tour and European-based DP World Tour, as well as the Ryder Cup.
(Reporting by Aadi Nair in Bengaluru; editing by Jane Wardell)