Rory McIlroy said it will be difficult for the PGA Tour and LIV Golf to reach an agreement so long as the Saudi-backed league continues to spend "irrationally."
Speaking at the CNBC CEO Council Forum, the world's No 2-ranked golfer doesn't see a pathway for the reunification of the professional golf world any time soon.
"You see some of these other sports that have been fractured for so long," McIlroy said, per ESPN. "You look at boxing for example, or you look at what's happened in motor racing in the United States with Indy and NASCAR and everything else, I think for golf in general it would be better if there was unification.
"But I just think with what's happened over the last few years, it's just going to be very difficult to be able to do that."
LIV Golf has totaled more than $1.4 billion in losses over its first four years of existence, according to a report from The Athletic last month.
However, that hasn't deterred the league, whose prize money expenditure for 2024 was roughly $400 million alone.
With several of the league's early big-money signings approaching the end of their initial contracts, Dustin Johnson has reportedly already agreed to a new deal while Bryson DeChambeau is also expected to recommit to the league early.
LIV is also expanding its format to 72 holes in 2026 as it seeks to earn Official World Golf Ranking points for its events.
A little less than $1.4 billion has been distributed to players thus far, with The Athletic estimating that outside funding has invested over $4.89 billion into the league.
That is more than three and a halftimes the recorded prize money.
"As someone who supports the traditional structure of men's professional golf, we have to realise we were trying to deal with people that were acting, in some ways, irrationally, just in terms of the capital they were allocating and the money they were spending," McIlroy said.
"It's been four or five years and there hasn't been a return yet, but they're going to have to keep spending that money to even just maintain what they have right now.
"A lot of these guys' contracts are up. They're going to ask for the same number or an even bigger number. LIV have spent five or six billion US dollars, and they're going to have to spend another five or six just to maintain where they are.
"I'm way more comfortable being on the PGA Tour side than on their side but who knows what'll happen?"