Perennial middleweight contender Derek Brunson made his 25th octagon appearance at UFC 285, taking on surging South African contender Dricus du Plessis.Entering the octagon on Saturday night, 'The One' attempted to bounce back from a second-round TKO loss to Jared Cannonier that ended a five-fight unbeaten run and also stopped his title run.Brunson took his opponent down early in the fight and clearly edged out the round with dominant grappling. While du Plessis looked tired, he dramatically shifted the momentum in round 2 after catching 'The One' with a left hook. 'Stillknocks' connected flush multiple times before Brunson went down, giving up full mount.The South African unleashed lethal ground and pound, which was enough for Brunson's corner to throw in the towel as the round ended.Takedown Defense@ChillemThreeboDricus Du Plessis TKOs Derek Brunson at UFC 28512128Dricus Du Plessis TKOs Derek Brunson at UFC 285 https://t.co/qistHKnST9The middleweight veteran took to Twitter in the immediate aftermath of his UFC 285 loss, seemingly alluding to retirement. Brunson congratulated his opponent and thanked everyone for watching his "career". The 39-year-old wrote:"Thanks for all who watched my career . Crazy fight tonight . My corner decided to stop it in the after the second rounds. Congrats to my opponent ."Derek Brunson@DerekBrunsonThanks for all who watched my career . Crazy fight tonight . My corner decided to stop it in the after the second rounds. Congrats to my opponent .6671230Thanks for all who watched my career . Crazy fight tonight . My corner decided to stop it in the after the second rounds. Congrats to my opponent .Derek Brunson's comments have led fans and fighters to speculate his retirementMMA Twitter seemingly agrees that Derek Brunson's latest comments hint at retirement. While fans and fighters unanimously showered respect on Brunson, some couldn't resist asking if he 'The One' really wants to retire.Former UFC lightweight Isaac Vallie-Flagg wrote:"Did you retire? If so it was an honor watching you and knowing you my man. All the best to you in whatever you decide from here on out. ❤️"ike vallie-flagg@IKEVF@DerekBrunson @PhotoAmy33 Did you retire? If so it was an honor watching you and knowing you my man. All the best to you in whatever you decide from here on out. 461@DerekBrunson @PhotoAmy33 Did you retire? If so it was an honor watching you and knowing you my man. All the best to you in whatever you decide from here on out. ❤️Pro Poker player turned nutrition coach TJ Jurkiewicz wrote:"Thank you for being a warrior"TJ Jurkiewicz | Nutrition Coach@tj_jurk@DerekBrunson Thank you for being a warrior1@DerekBrunson Thank you for being a warriorWhile there is no confirmation on whether Brunson plans to call it a day, some suggest that he should.Dawn@DawnWasTaken_@DerekBrunson That first sentence sounds like you’re retiring?229@DerekBrunson That first sentence sounds like you’re retiring?SportGenius@BetThenWin@DawnWasTaken_ @DerekBrunson He should1@DawnWasTaken_ @DerekBrunson He should@pablotalksUFC wrote:"Call it a career chief"PabloTalksUFC@pablotalksUFC@DerekBrunson Call it a career chief2@DerekBrunson Call it a career chief@tonyv1299 wrote:"It's been a hell of a ride Derek. Nothing to hang your head about if you put down the gloves. Wishing you the best."tony@tonyv1299@DerekBrunson It's been a hell of a ride Derek. Nothing to hang your head about if you put down the gloves. Wishing you the best.20@DerekBrunson It's been a hell of a ride Derek. Nothing to hang your head about if you put down the gloves. Wishing you the best.Check out more reactions from UFC fans and fighters below:Alex Behunin@AlexBehunin@DerekBrunson Thank you for the memories Derek!You’re the man1401@DerekBrunson Thank you for the memories Derek!You’re the manTanner Boser@BulldozerBoser@DerekBrunson Always great to see you fight. Fan for life.126@DerekBrunson Always great to see you fight. Fan for life.bjpenndotcom@bjpenndotcom@DerekBrunson Congrats on a great career 🏼2261@DerekBrunson Congrats on a great career 👏🏼Brendan Allen@BrendanAllenMMA@DerekBrunson OG!! #respect541@DerekBrunson OG!! #respectHerbert Burns@HerbertBurnsMMA@DerekBrunson 🏾🏾🏾19@DerekBrunson 🙏🏾🙏🏾🙏🏾Christian Harder@realcharder30@DerekBrunson Much respect 🫡3@DerekBrunson Much respect 🫡Josh@JUchiha909@DerekBrunson Been great watching you through the years26@DerekBrunson Been great watching you through the years https://t.co/mTCsJyN1ZLRath_of_Khan@Rouge5delta@DerekBrunson @CTaylor_96 It was an honor sir thank you 75@DerekBrunson @CTaylor_96 It was an honor sir thank you 🙏Majick@Majick666@DerekBrunson Thanks for the highlights! Blonde Brunson will always be legend.@DerekBrunson Thanks for the highlights! Blonde Brunson will always be legend.If Derek Brunson does retire, he will do so with a stellar 23-9 record.