The PGA is still in negotiations with Saudi Arabia's public investment fund (PIF), which financially backed LIV and got several big names to break away from the established tour in 2022 and 2023.
Those players were suspended indefinitely by the PGA Tour, with the most recent being world No.3 Jon Rahm, who signed with LIV in December.
Since then, a consortium of US-based sports franchise owners called the Strategic Sports Group (SSG) has made an initial $US1.5 billion ($A2.3 billion) investment to become minority owners of PGA Tour Enterprises, the tour's new for-profit wing.
But if the PGA and PIF do complete a deal, it remains to be seen how that will affect the future of LIV and its players.
Four-time major winner Rory McIlroy - once the rebel tour's fiercest critic - recently did an about-face, saying LIV players who wish to return to the PGA Tour should be able to do so without sanction.
"I would say that there's a handful of players on LIV that would make the tour a better place," Thomas said on Tuesday ahead of the WM Phoenix Open.
"But I'm definitely not in agreement that they should just be able to come back that easily."
Spieth and Fowler have also made clear in recent days that they don't align with McIlroy's sudden mellowing.
"There's a lot of us that made sacrifices and were very - whether it's true to our word, or what we believe in, or just didn't make that decision," Thomas said.
"I totally understand things are changing and things are getting better, but ... I would have a hard time with it, a lot of guys would have a hard time with it.
"I'm sure we don't need to convince you why we would have a hard time with it.
"There's a scenario somewhere ... of some guys being back, but when and what that is, I have no idea."
