Conor McGregor tweets: 'I have decided to retire young'

Speculation runs rampant about McGregor's retirement tweet (1:32)

ESPN MMA writer Brett Okamoto explains why Conor McGregor's tweet about retiring young is peculiar and speculates on the motives behind it. (1:32)

UFC featherweight champion Conor McGregor will not fight Nate Diaz at UFC 200 on July 9 in Las Vegas. Whether he will fight again period remains a question.

UFC president Dana White announced Tuesday night on SportsCenter that the promotion has pulled McGregor from the main event at UFC 200, due to the Irishman's unwillingness to fly to Las Vegas and participate in mandatory promotional activities.

The news came hours after McGregor sent the MMA world into chaos by tweeting that he has decided to retire young.

ESPN has attempted to contact McGregor and members of his camp, but no one was available for immediate comment.

White, meanwhile, said he had been in communication with McGregor's management throughout Tuesday. He said he could not speak on McGregor's future, other than his status at UFC 200.

"We pulled Conor McGregor from UFC 200 and we're working on other fights right now," White said. "Conor did not want to come to Las Vegas and film the commercial and be a part of the marketing. He's in Iceland training.

"Is Conor retiring? Only he can answer that question. I don't know."

White went on to say the UFC still has a "good relationship" with McGregor (19-3) and that he "respects Conor as a fighter" but added that promotional obligations are mandatory.

The UFC has faced a similar situation before.

Nick Diaz, Nate Diaz's older brother, was pulled from a title fight against Georges St-Pierre in 2011 after he skipped a news conference. Ironically, Nick Diaz was eventually re-added to the card and ended up headlining it against BJ Penn when St-Pierre pulled out with an injury.

According to White, Nate Diaz (19-10) was scheduled to arrive in Las Vegas on Tuesday evening. The UFC intends to meet with Diaz and discuss potential options that could keep him on the July 9 card.

McGregor, 27, would retire with a UFC record of 7-1. He took the MMA world by storm in 2015, with three knockout wins against Dennis Siver, Chad Mendes and Jose Aldo. The Dublin native set a UFC record for quickest finish in a title fight by knocking Jose Aldo out cold in 13 seconds at UFC 194 in December.

He suffered the first loss of his UFC career March 5, in a 170-pound nontitle fight against Diaz at UFC 196 in Las Vegas. McGregor was originally supposed to fight Rafael dos Anjos for the lightweight championship, but dos Anjos withdrew due to injury. Diaz stepped up on 11 days' notice and submitted McGregor in the second round.

McGregor's tweet was posted one week after Joao Carvalho died from injuries suffered during a fight earlier this month that McGregor attended.

McGregor, who was ringside at Carvalho's fight in Dublin, posted a message to his Facebook account last week.

"To see a young man doing what he loves, competing for a chance at a better life, and then to have it taken away is truly heartbreaking," he wrote.