Watch: Rory McIlroy roasts Phil Mickelson over Ryder Cup betting allegations

Responding to questions from reporters at the FedEx St. Jude Championship, McIlroy said of Mickelson, "At least he can bet on the Ryder Cup this year, cause he won't be apart of it." 

While McIlroy chuckled after his comment, Mickelson's alleged actions are no laughing matter. The 53-year-old has lost nearly $100 million and wagered almost $1 billion over the past 30 years, according to excerpts obtained by Golf Digest from a soon-to-be-released book by betting icon Billy Walters. Walters shared an alarming story, claiming that Mickelson asked him to lay a $400k bet ahead of the 2012 Ryder Cup because he felt "supremely confident." Ultimately, Walters didn't place the bet, but if what he says is true, it's not hard to wonder if Mickelson had successfully made similar wagers in the past. 

A key defector to LIV Golf during its back-and-forth with the PGA Tour, Mickelson's nudge the rival's way was undoubtedly a driving force leading to the merger between the two leagues. The waters only get muddier when considering LIV Golf's financial backing and Mickelson's alleged high-stakes wagering. Dot-connecting aside, it's a bad look for Mickelson, who has openly admitted to battling a gambling addiction. 

Mickelson initially "passed" on commenting on the situation. However, following a change of heart, he released a statement saying he "never" bet on the Ryder Cup. 

"While it is well known that I always enjoy a friendly wager on the course, I would never undermine the integrity of the game," Mickelson said.