Floyd Mayweather has technically retired twice before, but that hasn't stopped other famed fighters from asking the undefeated boxer to defend his legacy.
After returning from retirement for a one-fight comeback in 2017, undefeated boxer Floyd Mayweather continues to recieve - and sometimes accept - challenges to fight again.
The famed fighter holds a perfect 50-0 record after defeating MMA fighter Conor McGregor in 2017. He was 49-0 going into the much-anticipated match after his 2015 retirement, which came after his defeat of Manny Pacquiao. Mayweather, 41, had already previously retired in 2007 after beating Ricky Hatton, but returned to fight from 2009 to 2015 and then again in 2017.
While McGregor was the first to call him out of retirement, he certainly was not the last. Many of Mayweather's past opponents seek revenge for undesired outcomes as others seek a new challenge.
Whether or not any of these taunts turn into actual fights is still unknown, but Canelo Alvarez, Khabib Nurmagomedov and Manny Pacquiao have all requested a rematch with the aging legend.
Here's a timeline of all the fighters who have recently called out Mayweather:
Canelo Alvarez: October 2018
WBC and WBA unified middleweight champion Canelo Alvarez (50-1-2) suffered his lone career loss when he lost to Mayweather (50-0) on Sept. 14, 2013 by majority decision.
Alvarez challenged Mayweather to a rematch of their 2013 fight, telling TMZ Sports that if Mayweather really wants to return to boxing, "I ask him to look my way to give a great fight to the fans."
Since retiring for a second time in 2015, Mayweather's one-fight return in 2017 was against Conor McGregor, an MMA fighter. Although McGregor agreed to box against Mayweather, Alvarez said he is tired of watching Mayweather make fights that "don't make sense." He added that he's ready to give the legendary boxer a real challenge with a rematch.
"He wants to continue hurting boxing by making fights that don't make sense ... and not giving boxing the credibility it deserves," Canelo told TMZ Sports.
Alvarez added: "Let's do the second fight. It's very important. We have something pending there, so let's make the second fight."
"Look, that's something that I would love," Alvarez told SI Now in October. "If he wants to come back and is still motivated to come back, he should do it right. He should do it right and give me the opportunity to have that rematch and demonstrate who is better."
Khabib Nurmagomedov: October 2018
UFC lightweight champion Khabib Nurmagomedov challenged Mayweather to a fight in the wake of his fourth-round submission of Conor McGregor on Oct. 6. Nurmagomedov offered his challenge on a video that surfaced on social media. Standing next to Leonard Ellerbe, CEO of Mayweather Productions, the fighter called the 41-year-old boxer out after his dominant win.
"Let's go Floyd, we have to fight now," Nurmagomedov said. "50–0 vs. 27–0, two guys who never lose. Let's go, why not? Because in the jungle, there's only one king. Of course I'm the king because he cannot drop McGregor, but I drop him easily. Let's go."
Nurmagomedov (27-0 MMA, 11-0 UFC) is pointing to the fact that he knocked down McGregor with an overhand right in the second round of their UFC 229 headliner this month before forcing McGregor to tap out in the fourth. In their boxing match last year, Mayweather defeated McGregor with a 10th-round TKO. He was unable to drop the former two-division UFC champ.
Mayweather accepted the challenge on Instagram writing, "CBS, Showtime and MGM Grand get the checkbook out!"
Manny Pacquiao: July 2018
Pacquiao lost to Mayweather in 2015 in the boxer's last big bout by unanimous decision. The fight went 12 rounds Manny Pacquiao requested a rematch against Mayweather in July after taking the Welterweight title belt against Lucas Matthysse. After knocking Matthysse out, reporters asked Pacquiao if he thought about who his next opponent would be.
Pacquiao, 39, said he wanted to return to the ring for a rematch of his much-anticipated 2015 clash with Mayweather.
"Mayweather? If he decides to go back to boxing then that is the time we are going to call the shots," he told reporters after his July win. "I have the belt, so it's up to him. If he wants to come back in boxing let's do a second one."
Mayweather responded on Instagram in September, saying "I'm coming back to fight Manny Pacquiao this year another 9 figure pay day on the way.".
Conor McGregor: July 2015
Mayweather retired again after defeating Manny Pacquiao by unanimous deicision in May 2015. Two months later, MMA fighter Conor McGregor told late night host Conan O'Brien that he would "box [Mayweather] if the opportunity arose," on his show, 'Conan.' Rumors swirled about Mayweather coming out of retirement to fight McGregor, who seemed determined to bring the legendary boxer out of retirement.
Trash talk and reported negotiations continued until Mayweather confirmed the fight in March 2017. He told the audience on his "Undefeated" tour, "I'm coming out of retirement just to fight Conor McGregor."
One week after Mayweather announced his return to the ring, McGregor also confirmed the match by screaming, "I am boxing!" after the Michael Conlan fight at Madison Square Garden.
After two years of back-and-forth insanity, an agreement was reached to bring Mayweather out of retirement for a one-time fight. McGregor-Mayweather finally happened on Aug. 26, 2017, as the two fought in the 'Money Fight.' With the 10th round TKO, Mayweather surpassed Hall of Famer Rocky Marciano's record of going 49–0.
In responding to Nurmagomedov's 2018 challenge, Mayweather decided to do the calling out this time - saying that he wanted to face McGregor once again in a rematch.
"McGregor was talking that s--t, so it ain't over," Mayweather told TMZ Sports. "After me and Khabib lock up, me and McGregor we gonna lock up again."