Floyd Mayweather has said he is coming out of retirement in 2020, working with UFC president Dana White "to bring the world another spectacular event".
Mayweather, the former five-weight world champion, said he was hanging up his gloves in 2017 after defeating UFC star Conor McGregor in a boxing match in Las Vegas.
The American did also come out of retirement momentarily on New Year's Day for a one-off exhibition bout with Japanese kickboxer Tenshin Nasukawa, knocking him down three times in the first round to win the fight.
But it looks like Mayweather is coming back based on his recent activity on Instagram.
The 50-0 fighter posted an image of himself and UFC boss White with the caption: "Dana White and I working together again to bring the world another spectacular event in 2020."
It was followed by another post, saying: "Coming out of retirement in 2020."
White reposted both of Mayweather's uploads.
Earlier this week, Mayweather said he would not be returning to boxing to protect his health.
"I've got calls to get back into the ring, but my health is my wealth," said Mayweather.
"Boxing is a very, very brutal sport. In the last few years, a lot of fighters have died inside that squared circle.
"You have got to know when to hang it up. I had a great career."
The 42-year-old says his only future fights will be exhibitions, like the one in January which saw him demolish Nasukawa in less than three minutes.
"I'll still travel and do exhibitions," said Mayweather. "I make great money doing exhibitions - between $10m and $30m.
"I think I make more doing that than most fighters make fighting."