Saul “Canelo” Alvarez and Kamaru Usman, the pound-for-pound No 1s in boxing and the UFC respectively, have continued to exchange barbs regarding a potential crossover bout. Speculation the two could meet in a boxing clash has ramped up the past few months, with UFC welterweight belt-holder Usman declaring last month <a href="https://www.thenationalnews.com/sport/ufc/2022/03/14/ufc-champion-kamaru-usman-vows-to-stop-canelo-alvarez-should-they-meet-in-crossover-bout/" target="_blank">he would stop the undisputed super middleweight champion</a> should a lucrative match-up materialise. The possible encounter has again been in the news this week, after Usman’s manager, Ali Abdelaziz, labelled Alvarez an “absolute chicken” for not wanting to face his client. After Alvarez bit back on social media, Usman stepped in, tweeting late on Wednesday: “Let’s just all relax… before somebody gets hurt.” That prompted a back-and-forward between the pair online, with Alvarez telling Usman he would have to bide his time, saying: “You calling me out right ? You want the pay day right ? So you know where, but sit down it's not your turn yet. I have a legacy to make.” Early on Thursday, Usman responded: “Enough said… you don’t want that smoke in a real fight. I hear you! Good luck champ.” Usman, 34, has held the welterweight title for three years, with five successful defences in that time – <a href="https://www.thenationalnews.com/sport/other-sport/ufc-251-kamaru-usman-beats-jorge-masvidal-to-retain-title-in-abu-dhabi-1.1047881" target="_blank">including once in Abu Dhabi, during the inaugural Fight Island in July 2020</a> – catapulting him to the top of the UFC’s pound-for-pound rankings. He is currently 15-0 in the promotion having most recently <a href="https://www.thenationalnews.com/sport/football/2021/11/07/kamaru-usman-defends-title-over-colby-covington-at-ufc-268/" target="_blank">defeated No 1-ranked challenger Colby Covington by unanimous decision </a>in their rematch at UFC 268 in November. Alvarez, meanwhile, has <a href="https://www.thenationalnews.com/sport/other-sport/2021/11/07/canelo-vs-plant-alvarez-knocks-out-plant-to-make-super-middleweight-history-in-pictures/" target="_blank">won 15 of his past 16 bouts</a> – he drew his first fight with Gennady Golovkin, in late 2017 - since losing to Floyd Mayweather in 2013. The Mexican, 31, has returned to light heavyweight to take on undefeated WBA (Super) champion Dmitry Bivol at T-Mobile Arena in Las Vegas next week. Alvarez and Usman are not the only boxing and MMA champions to be sizing each other up for a blockbuster crossover bout, with heavyweight champions Tyson Fury and Francis Ngannou also keen to clash. Fury retained his WBC heavyweight title with a stoppage win over Dillian Whyte on Saturday, and UFC champion Ngannou joined the British fighter in the ring after the bout. Ngannou has since said he would only be interested in renewing his UFC contract if <a href="https://www.thenationalnews.com/sport/ufc/2022/04/26/francis-ngannou-wont-sign-new-ufc-deal-unless-tyson-fury-bout-is-part-of-agreement/" target="_blank">it includes the option to face Fury in a crossover fight</a>.