UFC star Conor McGregor has singled out a scientist who has backed vaccines and stronger government measures to curb rising Covid cases.
A day after using a swiftly-deleted tweet to claim that vaccines "have not worked whatsoever" to stop the spread of Covid, McGregor shared a photo of Professor Luke O'Neill, one of the most high-profile Irish experts on the pandemic.
In a lighthearted portrait, the immunologist at Trinity College Dublin was seen carrying a brightly-colored physical depiction of the virus while grinning in a laboratory and wearing a light blue t-shirt under his lab coat bearing a message backing science.
Professor O'Neill has just released a book, 'Keep Calm and Trust the Science', and conceded last week that "we simply don't know" what is behind a surge in Covid cases that has affected Ireland and much of the world, warning that "every western European country is in trouble".
The multi-award winning academic, who has been recognized for inspiring emerging scientists, has recently used his own Twitter account, which has a following of almost 100,000, to advocate Pfizer booster shots as providing "huge protection" to a "dramatic effect".
"Guys, I'm not an immunologist," admitted McGregor, echoing the jibes of some of his critics.
"I know nothing of strong immune systems or physical health, fitness and wellbeing. This guy does."
McGregor then tagged O'Neill's account, effectively highlighting how his own vast following of more than nine million could find the scientist.
The confessional tweet seemed somewhat curious given that McGregor regularly encourages fans to invest in and mimic his health and fitness techniques. He has also been known to hold forth on issues around wellbeing and staying healthy.
That led some readers to question the sincerity of McGregor's message, while none of the immediate respondents to quote his tweet did so in a positive manner towards O'Neill.
Several laughed and praised McGregor for variously being "awake", "smart" and "wise". Others made unflattering remarks about O'Neill's appearance.
"Someone please translate this for me," asked one, perhaps alluding to the fury McGregor had previously vented at Ireland's leaders over their handling of the rise in cases. "Is this a sarcastic dig at the Irish Government?"
In a predictable climax, McGregor deleted the tweet within hours - but not before O'Neill had become the center of attention for a deluge of the former champion's admirers.
The 33-year-old deployed the same tactic when he mocked former rival Khabib Nurmagomedov over his father's death from complications relating to Covid earlier this year.
He also deleted a later outburst in which he told Nurmagomedov's manager, Ali Abdelaziz, that he would celebrate his death.
The tweet to O'Neill may have been a response to his target's opinion column in the Irish Sunday Independent on Sunday.
The piece claimed that the country would "ride out the current upsurge" with the help of "boosters, antigen testing and vaccine passports".