#2. Colby Covington
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Colby Covington has teased a bout with Khamzat Chimaev following his narrow loss to Kamaru Usman at UFC 268. Covington has proven himself to be a world-class fighter and could easily become Chimaev's toughest opponent to date.
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Covington's strengths are undoubtedly his wrestling and ridiculous cardio. While Chimaev also seems to be a very talented grappler, we are yet to see him go toe-to-toe with someone on the level of 'Chaos'.
Additionally, you would imagine that if the fight were to go into a third, fourth, or fifth round, Covington would be better prepared. Each of Covington's last five bouts has all gone into the fifth round. He has consistently shown his ability to grind away late.
#1. Kamaru Usman
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Kamaru Usman vs. Khamzat Chimaev would be a blockbuster of a fight. A potential match-up next year may not be outside the realm of possibility either. While Usman will likely face Leon Edwards next, Chimaev could conceivably be the next fight after that.
Usman has exceptional wrestling, which might be enough to match that of Chimaev. One would also assume that Usman is the better striker considering his knockouts of Gilbert Burns and Jorge Masvidal.
Given Usman has established himself as the clear number one guy in the welterweight division, there is simply no man more likely to hand Khamzat Chimaev the first loss of his career.