• Floyd Mayweather and Conor McGregor have reignited their war of words on social media – and they’ve even asked fans to get involved.
  • They’ve been tangled in an online bout since Mayweather beat McGregor in a boxing-rules contest in Las Vegas two years ago.
  • In the past week, both retired fighters posted photos of their 2017 fight and asked their millions of followers to caption the snaps.
  • Visit Business Insider’s homepage for more stories.

Floyd Mayweather and Conor McGregor have reignited their long-standing feud, even encouraging fans to get involved in their war of words on Instagram.

McGregor caused controversy in the build-up to their 2017 fight in Las Vegas with several comments widely described as racist, including that he was “half-black from the belly button down.”

And since Mayweather’s 10th-round stoppage win over the Irishman, which saw him take his professional record in the ring to 50-0, the pair have continually exchanged blows on social media, adding fuel to the fire.

Last Monday, Mayweather posted a face-off photo from their 2017 promotional tour with the words “Caption This.”

Then on Thursday, McGregor posted a photo from the 2017 bout and encouraged his more than 30 million followers to caption it.

Read more: Conor McGregor just claimed he's a billionaire in an Instagram post, but it's unlikely that's even close to being true

http://instagr.am/p/B07RQyFpSTB

Mayweather took little time to fire another jab back. On Friday, he posted a photo of him landing a hefty shot to the Irishman's chin during his stoppage win, adding, "GIVE ME THE BEST CAPTION YOU CAN THINK OF."

http://instagr.am/p/B09n1xpFHS8

It's not the first time the rivals have been at each other's throat.

In January 2018, Mayweather criticized McGregor over reports that the former UFC champion had gotten into trouble with Irish gangsters. Mayweather posted The Independent's headline on Twitter and said: "I already f---ed you up in 2017 now they about to f--- you up in 2018. You're about to start your new year off with a bang."

Later that year, it was McGregor on the offensive as he unleashed an expletive-laden attack on Mayweather after the boxer announced he would fight the Japanese kickboxer Tenshin Nasukawa, controversially comparing the event to the "Rush Hour" films.

A Mayweather-McGregor rematch is unlikely - the fight was such a convincing win for Mayweather, who announced his retirement afterward.

McGregor, who most recently lost to Khabib Nurmagomedov at UFC 229 in 2018, has remained coy about if he'll return to the octagon, but the UFC boss Dana White has refused to rule out a rematch between McGregor and the Russian this year.