Commissioner Jay Monahan says LIV Golf participants "need" the PGA Tour but insists the Tour will not allow players to "freeride off its loyal members".
Monahan reflected on a "unfortunate week" created by "unfortunate decisions" that has seen a string of high-profile players sign up to the Saudi-back breakaway circuit.
Patrick Reed, Pat Perez and Bryson DeChambeau are among the latest players to commit to playing in the controversial Saudi-backed circuit, following on from the likes of Dustin Johnson, Sergio Garcia and Phil Mickelson.
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In response, the PGA Tour suspended all members involved in this week's inaugural event at the Centurion Club and said they will hand out the same penalty to any golfer wanting to feature in any future tournaments.
"I guess I would answer the question (of why players cannot do both) by asking a question, and that is, why do they need us so badly? Because those players have chosen to sign multi-year lucrative contracts to play in a series of exhibition matches against the same players over and over again," Monahan said at the RBC Canadian Open.
"You look at that versus what we see here today, and that's why they need us so badly. You've got true, pure competition, the best players in the world here at the RBC Canadian Open, with millions of fans watching, and in this game it's true and pure competition that creates the profile and presence of the world's greatest players.
"That's why they need us, that's what we do, but we're not going to allow players to free-ride off of our loyal members, the best players in the world."
Saudi Arabia's human rights record has raised serious questions surrounding the morality of the lucrative deals being handed to competing players. Monahan shut down suggestions from some players that the LIV Golf Series supported the 'growth of the game'.
"It (the money) is not an issue for me, because I don't work for the Saudi Arabian government," he said. "But it probably is an issue for players that chose to go and take that money. I think you have to ask yourself the question, why?
"Why is this group spending so much money, billions of dollars, recruiting players and chasing a concept with no possibility of a return? At the same time there has been a lot of question and comments about 'growth of the game' and I ask, 'how is this good for the game we love?'"
Those defending the event have cited previous tournaments staged by other tours in Saudi Arabia, questioning how they differ from the LIV Golf Series, although Monahan insisted the two were 'distinctly' different.
"They are two different things," replied Monahan. "The Saudi International was an individual event recognised by a sanctioned tour. The series is a group of events, predominantly based in North America, so when you look at that you realise a player would not be able to fulfil their responsibilities as a member.
"They are two very distinctly different things. In protecting our loyal members, we can't allow players to free-ride off of them."
"I would ask any player that has left or that would ever consider leaving, have you ever had to apologise for being a member of the PGA Tour?" he added.
He preceded to express his optimism regarding the future of the PGA Tour, perhaps fittingly underlined in Toronto on Sunday as Justin Rose threatened to shoot 59 while Rory McIlroy, Justin Thomas and Tony Finau put on a show at the top of the leaderboard.
"We're constantly evolving, I couldn't be more excited about where we go from here," he said. "I talked about the fact we're going to grow faster over the next 10 years than we have at any point in our history.
"Life is all about meaning and purpose and we're an organisation with meaning and purpose. The best players in the world make wonderful things happen on this platform day in day out, week in week out.
"This organisation is going to continue to evolve in the face and shape of the great members we have here. We're going to continue to advocate and grow this game in the right way and continue to make meaningful contributions as an organisation. I couldn't be more excited about the future we all have together."