Rory McIlroy aimed a not too subtle dig at the ever-growing cohort of top golfers who have ditched the traditional PGA Tour in favour of joining the Saudi-backed LIV Golf Series.
His compatriot Graeme McDowell is among those who have chosen to join the lucrative new venture which hosts its inaugural event this week in London.
McIlroy has been one of the most vocal critics of the LIV project since it became a legitimate threat to the established order.
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And speaking ahead of playing the Canadian Open, McIlroy chose his words carefully but lobbed one sharp observation in the direction of Mickelson, McDowell, Ian Poulter, Lee Westwood and company.
"I understand what their goals and their ambitions are in their life," he said.
"I'm certainly not knocking anyone for going. It's their life, it's their decision, they can live it the way they want to. But for me I want to play on the PGA Tour against the best players in the world.
"And I think for me, speaking to a few people yesterday and one of the comments was, anything, any decision that you make in your life that's purely for money usually doesn't end up going the right way. "
When pressed on whether the golfing establishment should punish LIV defectors by banning them from marquee events like majors and the Ryder Cup though, McIlroy felt that would be too extreme a reaction.
He stated: "Yes I still think they should be able to (participate in the Ryder Cup). They have been such a part of the Ryder Cup.
"Look at the history that Poults has with the Ryder Cup. It would be such a shame for him not to be involved going forward, whether that's as a vice-captain or a captain or maybe one last time in a playing capacity.
"It's the same with G-Mac and a lot of these guys. It's hard because they're playing in defiance of the Tour and whatever else is going on, but I just think everyone just needs to get in the room and figure it out.
"I felt the professional game was on a nice trajectory where everything was becoming more cohesive, and now it's becoming more fractured again, and I don't think that's a good thing.”
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