Conor McGregor posted and deleted a tweet which appeared to mock the death of Khabib Nurmagomedov's father late last night.
The Irishman has had a long-standing rivalry with Nurmagomedov which included a heated 2018 fight at UFC 229 which ended with a win for the Russian in the fourth round.
But despite settling their rivalry in the cage, the pair have never seen eye-to-eye, with McGregor's post last night a response to Nurmagomedov saying that "good always defeats evil" in reference to Dustin Poirier's recent win over the former lightweight champion.
Nurmagomedov posted in the aftermath of McGregor's trilogy bout with Poirier that he was "very happy" for Poirier, and said he hopes that he will win the belt by the end of the year.
And in a since-deleted reply two weeks later, the Irishman said: “Covid is good and father is evil?”
The Russian former champion's father Abdulmanap passed away last year after suffering a stroke, having battled coronavirus for most of his final months.
His son opted to retire from MMA competition after defending his title one more time following his father's death, saying that his mother wanted him to spend more time at home with his family.
This isn't the first time McGregor has mocked Nurmagomedov, telling ESPN in the build-up to his bout with Poirier that he felt his rival had done "nothing in the sport".
"Where is he gone though, where is he now?" McGregor said when asked in a recent interview for his thoughts on the Russian.
And when reporter Stephen A Smith answered by saying he was retired McGregor replied: "Why? he went sprinting, he’s gone, s*** his jocks, looking fat, roided up.
"He has done nothing in the sport. F***all he has done in the sport.”
The pair's rivalry seemed to start around the end of 2016 when McGregor was given the chance to fight Eddie Alvarez for the lightweight title in place of Nurmagomedov.
Nurmagomedov had signed two bout agreements to face Alvarez at Madison Square Garden, but he argued that he was used as a negotiating tactic by the UFC to convince McGregor to instead take the fight.
And while the Russian did call out McGregor in his post-fight interview after defeating Michael Johnson on the undercard, the feud wouldn't really heat up until well over a year later.
As Nurmagomedov was preparing for a shot at the vacant lightweight belt at UFC 223, he ran into McGregor's teammate Artem Lobov in the hotel lobby where the pair were staying ahead of the fight night, on which Lobov was also fighting.
And after an altercation between the two, McGregor hopped on a private jet from Dublin to New York with a group of friends to ambush the Russian at the pre-fight press conference.
McGregor ended up throwing an object through the window of a fighter bus on which Nurmagomedov was sitting, which resulted in him spending a night in jail before eventually fighting his rival.
The pair appeared to be friends early in their UFC careers, taking photos together in Las Vegas, but evidently the relationship turned sour over the years, and even after their fight the barbs have never ceased between them.
