'You are a s*** human': UFC star Justin Gaethje lashes out at Conor McGregor in Twitter blast

UFC lightweight contender Justin Gaethje has issued a challenge to former 'champ champ' Conor McGregor in the wake of Khabib Nurmagomedov's victory against Dustin Poirier at UFC 242.

Gaethje and McGregor were reported to be in talks to fight in July in what would have been the Irishman's first fight since losing to Nurmagomedov in their hotly-contested grudge match last October. But a hand injury suffered in training by the Irishman nixed any such plans.

With McGregor understood to be contemplating a return to the cage later this year or early in 2020, 155lb buzzsaw Gaethje wants to renew his rivalry with the controversial fighter and took to social media in the aftermath of Saturday's UFC 242 to call out the Dubliner.

McGregor, who has been vocal on social media in recent months, issued a message following Khabib's win to "book my rematch for Moscow," which prompted Gaethje to blast him on Twitter.

"You're a tool," Gaethje wrote. "You have lost everything already. You are a s*** human, father, and husband. F*** you."

It should be noted that McGregor is unmarried.

The 20-2 Gaethje is likely referring to the series of outside-of-the-cage incidents which have marred McGregor's personal life in recent months, including footage released by TMZ which appeared to show him striking an older man in a Dublin pub.

Gaethje has won successive lightweight fights against Edson Barboza and James Vick, both by first-round knockout, and sees the No.3-ranked McGregor as the logical next test in a division which is starting to settle down again following Nurmagomedov's title victory in Abu Dhabi. 

Tony Ferguson is the most likely next candidate to challenge the Russian after four failed attempts to book that fight in recent years, leaving an opportunity for the remainder of the lightweight elite to scramble to position themselves as the next logical contender at 155lbs.