Conor McGregor
McGregor could return to action in September. Getty

Conor McGregor insists he is in negotiations over his next opponent inside the UFC Octagon, listing Tony Ferguson, Khabib Nurmagomedov, Nate Diaz and Floyd Mayweather as the options on the table.

McGregor remains the UFC's lightweight world champion but is yet to defend the belt he took off Eddie Alvarez back in November 2016, having stepped away from the sport for the birth of his first child followed by his foray into boxing to take on the undefeated pound-for-pound king Mayweather last August.

First in line to challenge the Dubliner for his title is Ferguson, the weight's interim champion. The 33-year-old will tangle with Nurmagomedov later this year for what UFC president Dana White describes as a fight that will decide the "true champion" of the lightweight division – having refused to confirm if McGregor might even be stripped of his belt before those two meet at UFC 223 in April.

Diaz and McGregor tore the house down in two bloody battles in 2016, with the Stockton-born fighter submitting "Notorious" in their first meeting before McGregor levelled the score with a majority decision victory six months later.

And after condemning the Irishman to a technical knockout decision inside the boxing ring last year, 40-year-old Mayweather has teased the possibility of a rematch inside the Octagon.

And when recently quizzed on his next move by reporter Adam Glyn in New York, McGregor explained: "I am currently in negotiations to face my next opponent. We have many options. There is the current interim lightweight champion, there is an undefeated Dagestani [Nurmagomedov], maybe a big Russian event. There's obviously the Nate Diaz trilogy. Of course, the Mayweather fight is there."

Twice in the past week, Mayweather has shared footage of himself entering the Octagon, with the caption 'Come at the king, you best not miss" – referencing a famous quote from The Wire's Omar Little.

"2018, Floyd 'Money' Mayweather, MMA. What are the odds, Paddy? What are the odds?" Mayweather says in one of the videos, seemingly a message to Irish bookmakers Paddy Power, who sponsored the five-weight world champion in last year's fight.

Reacting to Mayweather's messages, McGregor said: "I'd do as I please against him inside the Octagon. But if he does do it – I know he is flirting with it – I would have respect for him. I think he would get his earned respect."