• Conor McGregor announced on Tuesday morning his surprise departure from MMA.
  • Some MMA figures – as recently as last month – had been predicting a 2019 comeback for him.
  • McGregor lost his most recent fight, a brawl with Khabib Nurmagomedov, which landed both fighters with a ban, which is due to expire in a few weeks.
  • McGregor’s behavior outside of sport continually makes headlines; he was arrested earlier this month after police said he got into a scuffle with a fan.

Conor McGregor, the notorious and controversial fighter, announced his shock resignation from MMA in the early hours of Tuesday morning.

McGregor wrote on Twitter: “I’ve decided to retire from the sport formally known as ‘Mixed Martial Art’ today.”

He went on to say: “I wish all my old colleagues well going forward in competition. I now join my former partners on this venture, already in retirement. Proper Pina Coladas on me fellas!”

There had been little indication before the tweet that McGregor might go.

As recently as last month, key figures in MMA were predicting that McGregor could fight again in 2019, perhaps even twice. But McGregor's career had recently been overshadowed by his behavior outside the ring.

Read more: Sylvester Stallone says the UFC is worried about Conor McGregor after the Irishman got 'publicly humiliated'

Earlier this month, McGregor was arrested in Florida and charged with robbery and criminal mischief after police say he slapped a phone out of the hand of a man trying to photograph him.

This photo provided by the Miami-Dade Corrections and Rehabilitation Department shows Conor McGregor. Authorities say mixed martial artist and boxer Conor McGregor has been arrested in South Florida for stealing the cellphone of someone who was trying to take his photo. A Miami Beach police report says the 30-year-old McGregor was arrested Monday, March 11, 2019 and charged with robbery and criminal mischief. (Miami-Dade Corrections and Rehabilitation Department via AP)

Foto: McGregor's mugshot from his arrest in Miami Beach, Florida.sourceAssociated Press

McGregor's most recent fight was against Khabib Nurmagomedov, who defeated him in October.

A brawl after that fight landed him a six-month suspension, which was due to expire on April 7.

The UFC boss Dana White said McGregor's retirement "totally makes sense" in text messages sent to ESPN journalist Brett Okamoto, which were then published on Twitter.

Referring to McGregor's Proper No. Twelve whiskey business, White said: "He has the money to retire and his whiskey is KILLIN it. It totally makes sense. If I was him I would retire too. He's retiring from fighting. Not from working. The whiskey will keep him busy and I'm sure he has other things he's working on."

Read more: McGregor's coach says the UFC star doesn't spend much money because his expensive clothes and cars are 'given to him'

White went on: "He has been so fun to watch!!! He has accomplished incredible things in this sport. I am so happy for him and I look forward to seeing him be as successful outside of the octagon as he was in it."

But not everybody in the industry believes McGregor.

Speaking to Sports Center, Okamoto said he is not treating it as an "official" retirement, even though White is.

MMA journalist Dan Shapiro reminded his social-media followers that McGregor retired once before, in April 2016, only to come back to the sport months later. He said: "This new retirement announcement can only mean that July 2019 will be both notorious and proper."

The Fox Sports radio host Jason Smith said he does not buy McGregor's retirement considering the Irishman had only just graced the Jimmy Fallon show and tweeted his statement hours later.

"So Conor McGregor went on Jimmy Fallon tonight, didn't retire, then tweets out he's retiring at 1.30 a.m.? I don't know that I buy this."

Fox Sports anchor Troy Hirsch tweeted: "Something tells me we'll see him in the octagon again."

McGregor had been linked with comeback fights against Donald "Cowboy" Cerrone and Nate Diaz, but retires five months after his UFC 229 loss to Khabib Nurmagomedov.