Conor McGregor's rivals are queuing up to take a pot-shot at the former UFC champion following his third 'retirement' in four years.

The former two-weight world champion made his announcement on Sunday morning, shortly after the conclusion of UFC 250 in which Amanda Nunes retained her featherweight title.

McGregor, who established himself as the biggest and richest star of the UFC, has been frustrated in his efforts to secure a fight this summer.

The Irishman had planned to compete three times in 2020 before the coronavirus crisis struck and sent sport into a tailwind.

McGregor had been advised by UFC president Dana White to wait until bitter rival Khabib Nurmagomedov had defended his title against Justin Gaethje in September.

Con or McGregor has announced his retirement

But the Dubliner's impatience appears to have overruled his boss as he called time on his career yet again following previous claims in 2016 and last year.

And Gaethje was the first of McGregor's rivals to react, tweeting: "Thankfully all of the elderly are still hiding in their homes. This guy is on another bender."

McGregor's tweet follows hot on the heels of other fighters' frustrations at not being able to fight during the pandemic.

Justin Gaethje has taken a swipe at McGregor

The lack of live gates has dramatically reduced the UFC's income and therefore the fighters' purses.

A fight featuring McGregor could bring in as much as $18million in Las Vegas but there are unlikely to be crowds in Sin City until the winter.

Light-heavyweight Jon Jones has also expressed his anger at his purses after clamouring for a fight with heavyweight contender Francis Ngannou.

And leading welterweight Jorge Masvidal is unhappy at the offer he was made to take on 170lb challenger Jorge Masvidal this summer.