Almost immediately after Justin Gaethje captured the 'BMF' title with a second-round head kick knockout of Dustin Poirier, Conor McGregor took to Twitter to express his interest in fighting for the symbolic belt. The former double champ's comments continued into the following day when he tweeted:"I KO him one shot. Guarantee it"Gaethje had previously expressed that he was uninterested in facing 'The Notorious,' who has been inactive for more than two years. That changed on Tuesday, however, as he responded to McGregor, stating:"Sign the contract big boy."McGregor followed with a one-word response, claiming:"Signed."Check out the tweets from Conor McGregor and Justin Gaethje below:Conor McGregor@TheNotoriousMMAI KO him one shot. Guarantee it341921258I KO him one shot. Guarantee itJustin Gaethje 🇺🇸@Justin_GaethjeSign the contract big boy. twitter.com/thenotoriousmm…258472079Sign the contract big boy. twitter.com/thenotoriousmm…Conor McGregor@TheNotoriousMMASigned. pic.twitter.com/SJKKDuoVYk14063887Signed. pic.twitter.com/SJKKDuoVYkFans reacted to the tweets by expressing their surprise. @vinnymcvega claimed:"What's the UFC cooking up? I'm here for it!"@JRomeo92 posted a throwback video of Mike Tyson making the comments that inspired Gaethje's tweet, captioning the post:"😤 😤 😤"@HomelanderMMA speculated on how Michael Chandler must be feeling:"Michael Chandler is crying right now"@Utd__Jeff suggested that the former double champ has changed:"McGregors unfortunately gone from Talk the Talk, Walk the Walk to just Talk the Talk. Ain’t gonna happen"@reynolds_ross claimed:"Justin really calling his bluff lol"@instamarko predicted that the bout would not go well for 'The Notorious':"Would be an interesting fight 3 years ago, but now I am afraid 2 leg kicks from Justin and Conor goes to ER lol"@piovincenzo_ does not believe the two will ever fight:"0% chance this happens"@phishphood44 speculated that McGregor must have been signing autographs:"Stop signing autographs and sign a contract to fight in the octagon. I use to defend you but at this point I think are only in TUF to market your need beer and beer"Check out the best fan reactions below:🌐M🌎J🌍McNally🌏@VinnyMcVegaWhat's the UFC cooking up? I'm here for it! twitter.com/Justin_Gaethje…1What's the UFC cooking up? I'm here for it! twitter.com/Justin_Gaethje…JRomeo@JRomeo92@Justin_Gaethje pic.twitter.com/IMLAUFW81b150575@Justin_Gaethje 😤😤😤 pic.twitter.com/IMLAUFW81bHomelander MMA@HomelanderMMA@Justin_Gaethje Michael Chandler is crying right now5233@Justin_Gaethje Michael Chandler is crying right nowJeff@Utd__Jeff@Justin_Gaethje McGregors unfortunately gone from Talk the Talk, Walk the Walk to just Talk the Talk. Ain’t gonna happen821@Justin_Gaethje McGregors unfortunately gone from Talk the Talk, Walk the Walk to just Talk the Talk. Ain’t gonna happenRoss Reynolds@reynolds_ross@Justin_Gaethje Justin really calling his bluff lol27@Justin_Gaethje Justin really calling his bluff lolMarko@instamarko@Justin_Gaethje Would be an interesting fight 3 years ago, but now I am afraid 2 leg kicks from Justin and Conor goes to ER lol133@Justin_Gaethje Would be an interesting fight 3 years ago, but now I am afraid 2 leg kicks from Justin and Conor goes to ER lolPio@piovincenzo_@Justin_Gaethje 0% chance this happens302@Justin_Gaethje 0% chance this happensCheese318@phishphood44@TheNotoriousMMA Stop signing autographs and sign a contract to fight in the octagon. I use to defend you but at this point I think are only in TUF to market your need beer and beer4@TheNotoriousMMA Stop signing autographs and sign a contract to fight in the octagon. I use to defend you but at this point I think are only in TUF to market your need beer and beerJake@JakeAndHoops@TheNotoriousMMA Gaethje sleeps you inside 2 rounds36@TheNotoriousMMA Gaethje sleeps you inside 2 roundsJeff Ferrara🎥📸@JFerraraF18@Justin_Gaethje Conor needs to pass USADA first tho 1@Justin_Gaethje Conor needs to pass USADA first tho 😂BUFO on the BEAT@BufoOnTheBeat@TheNotoriousMMA pic.twitter.com/jIOzCYI5bX5122@TheNotoriousMMA pic.twitter.com/jIOzCYI5bXCold DEAD Hands@ColdDEADHands7@Justin_Gaethje He's not gonna do it unless there's millions involved. Its not about the fight anymore for @TheNotoriousMMA, its about simply money... Money can't buy drive, or heart. But he knows that from his last few fights.@Justin_Gaethje He's not gonna do it unless there's millions involved. Its not about the fight anymore for @TheNotoriousMMA, its about simply money... Money can't buy drive, or heart. But he knows that from his last few fights.KMM 👑@KodyMatchmaking@TheNotoriousMMA naa if this is legit that's shit for Chandler@TheNotoriousMMA naa if this is legit that's shit for ChandlerWhat did Justin Gaethje previously say about facing Conor McGregor?Following UFC 291, Conor McGregor called out Justin Gaethje for a 'BMF' title fight. In his post-fight press conference, 'The Highlight' downplayed his interest in the bout, stating:"I think he's turned me down six times and usually, you have to lose to fight him... I'm not going to fight someone on steroids. I've never taken steroids in my life and never will - well, maybe when I retire I might - but I've never taken steroids and I don't want to fight someone that is cheating. I probably shouldn't even say that if I want the fight, but it's the truth."Check out Justin Gaethje's comments on Conor McGregor below:MMAFighting.com@MMAFightingJustin Gaethje responds to Conor McGregor: “I’m not gonna fight someone on steroids” #UFC291 pic.twitter.com/DMd7vwnYUy259241604Justin Gaethje responds to Conor McGregor: “I’m not gonna fight someone on steroids” 😬 #UFC291 pic.twitter.com/DMd7vwnYUyWhile McGregor had appeared set to face Michael Chandler later this year after coaching opposing sides on season 31 of The Ultimate Fighter, it is unclear if the pair will clash. 'The Notorious' reportedly failed to enter the USADA testing pool on time to meet the six-month requirement needed to return. Furthermore, Gaethje appears likely to fight for the lightweight title after his knockout victory over Dustin Poirier.