Rory McIlroy labelled breakaway players joining the LIV Golf International Series as "duplicitous" before Brooks Koepka became the latest high-profile name to leave the PGA Tour.
McIlroy has been a critic of LIV Golf, the controversial Saudi-backed competition, with opponents accusing the breakaway league of sportswashing.
However, that has not stopped the likes of Dustin Johnson, Phil Mickelson, Bryson DeChambeau and Sergio Garcia leaving the PGA Tour, who have indefinitely banned the defectors from returning.
Koepka was confirmed on Wednesday as the next big name to join and is the ninth major winner to sign for LIV Golf, with world number 20 Abraham Ancer also being linked with the tournament.
Four-time major winner Koepka refused to discuss LIV Golf at last week's U.S. Open, where he said he was "tired of conversations" and debates were "throwing a black cloud" over the third major of 2022.
Koepka subsequently withdrew from the Travelers Championship, which is the next PGA Tour event on Thursday, and will feature at the second LIV Golf event in Portland.
That has led to more debate around the breakaway league, and McIlroy feels his fellow golfers are not staying true to their word.
"Am I surprised?" McIlroy told reporters in Connecticut before Koepka's switch was confirmed. "Yes, because of what he said previously.
"I think that's why I'm surprised at a lot of these guys because they say one thing and then they do another, and I don't understand that and I don't know if that's for legal reasons or if they can't – I have no idea.
"But it's pretty duplicitous on their part to say one thing and then do another thing…the whole way through, in public and private, all of it."
McIlroy has enjoyed an upturn in fortunes over the last month, triumphing at the Canadian Open before finishing in a tie for fifth at the U.S. Open.
The 33-year-old admitted that tiredness is becoming a factor as he prepares for his fourth tournament in as many weeks, but remains excited to compete at the Travelers Championship.
"I got a night in my own bed down in Florida on Monday night, which was really nice," he added.
"But, yes, I came back up here yesterday and played the pro-am today and going to get an early night tonight. I've got an early start again tomorrow.
"But excited to get going and especially continuing the run of form I'm on. I'm playing some really good golf and I want to continue trying to do that.
"I think the three weeks that I've played, like Memorial's a very demanding golf course. Canada wasn't so demanding but when you get yourself in contention and you play a weekend like that, then that takes quite a lot out of you. And then you follow that up with a US Open. So I think it's a combination of everything.
"Mentally I'm totally fine, but it will be nice to sort of rest up this afternoon and get another good night's sleep and get ready to play tomorrow.
"But four weeks in a row is pretty rare for me these days. I haven't played four in a row in a while and you start to remember why!"