Allegations that Phil Mickelson tried to bet on a Ryder Cup he played in surfaced on Thursday and Rory McIlroy took a nasty shot at the LIV Golfer over it.

If Rory McIlroy and Phil Mickelson were ever cordial, that time has long since passed.

When the latter joined LIV Golf and became a vocal anti-PGA Tour voice, the former seemingly developed a personal vendetta against Mickelson. He was even seen in a clip on the Netflix docuseries Full Swing in the training room at the TOUR Championship saying, "F*** you, Phil!" to the cameras.

Now he might've taken his nastiest shot at Mickelson yet.

On Thursday, a former partner of Mickelson's made several allegations about the six-time major champion's excessive and problematic gambling in the past. One of the wildest was that he tried to bet $400,000 on the 2012 Ryder Cup on the United States team that Mickelson played on. Infamously, that competition led to the Sunday "Miracle at Medinah" and a historic European victory over the Americans.

Mickelson denies these allegations.

So after McIlroy's first round in Memphis at the FedEx St. Jude Championship, he was asked about the allegations of Mickelson betting on the Ryder Cup. And he took a shot at his adversary, saying, "At least he can bet on the Ryder Cup this year because he won't be a part of it."

Rory McIlroy fires viscious shot at Phil Mickelson over alleged Ryder Cup bet

Mickelson's battles as a gambling addict — something that was chronicled in detail in Alan Shipnuck's "Phil" — have been widely noted over the year. Fire Pit Collective even noted on Thursday in the wake of the allegations that he's undergone "hundreds of hours of therapy" to get past that part of his life, which he seemingly has.

Look, I've been a staunch supporter of McIlroy for years. But this might've been a little too razor-sharp of a jab at Mickelson in this instance. Yes, you could spin it as him simply jabbing at Phil for not being close to playing in the 2023 Ryder Cup, but to bring the betting part of it into the equation was uncalled for.

Alas, Rory fired another shot that won't be taken back and is sure to reach virality in the golfing world. It's probably something he'll also have to answer for too.