When Roger Federer beat Marin Cilic in an epic five-setter in the final of the Australian Open, he won his 20th Grand Slam title.Federer had not dropped a single set on his way to the final, but today, he found himself under heavy pressure, break point down in the opening game of the deciding set. However, he saved that break point and then he surged.Speaking after the match the Swiss maestro said, "You guys, you fill the stadiums, you make me nervous. You make me go out and practise. I'd just like to thank you for everything, It wouldn't be the same without you, thank you"."Marin's team as well. You guys work hard, all the best."Federer then shook his head and proceeded to express his gratitude for his team before he was rendered speechless with emotion. He stepped away from the microphone with tears streaming down his cheeks.All was good at this point. Until, Federer's eagle-eyed fans noticed something that drove the tennis world crazy.After every Slam win, the 36-year-old proclaims his love for the fans and promises them that he would be back next year to see them and to defend his crown, or at least that he hopes to be back. This time, though, he omitted that phrase. Whether he forgot to mention it amidst the overflow of emotions or not, the fans started speculating about his possible retirement.Roger Federer, is he going to retire this year?He didn't say he'll be back this year.#GOAT #AusOpen #20GrandSlams@BBCSport #bbcTennis— Mazhar (@Mazhar_7_) January 28, 2018Is Roger Federer going to retire? No mention of his customary "see you next year" and strangely emotional about winning considering how calm he was last year after beating his worst nightmare. Think 2018 could be the last year in a legendary career for @rogerfederer #AusOpen— Nawaz (@NawazITPS) January 28, 2018🚨CONSPIRACY THEORY🚨: Federer is crying because his going to retire at the end of the year and he hasn't said anything to anyone else yet. That's why this win means a lot to him because it will be his last ever #AusOpen and his happy he won for the last time.— Amy... (@xMissxAmyx) January 28, 2018Soon, speculation turned to a possibility, and a lot of fans certainly are not ready.please don't retire Roger— mslkaka (@GorgeousROGER) January 28, 2018I’m not ready for the possibility of Federer retiring 💔— Thaís (@thais__ferrari) January 28, 2018*sees people talking about Federer retiring**logs off Twitter**cries**runs away**lives in denial* pic.twitter.com/6V2Mf1zmC5— Kristina Borojevic (@kikiborojevic) January 28, 2018Roger Federer the true people's champion. Once in a lifetime talent. Never retire Rog.— Medium size daddy (@JRobes_pierre) January 28, 2018I swear when Federer decides to retire I don't know what tennis will do without him. Yes there's djokovic, Nadal etc but it won't be the same without him— Headless Chicken (@perilladerafa) January 28, 2018No "see you next year" from Federer. Don't want to read too much into it, but I dread the day he retires. Never retire, please. #AusOpen— J L (@mufc_jl) January 28, 2018It is unlikely that Federer will retire immediately - he must not, never - but a day will come when he will. We can only hope that 'that' day does not come any sooner than it is meant to be.