Islam Makhachev recently explained why Kamaru Usman should be his first title defense at welterweight and called the former 170-pound champion his "hardest fight" in the division.Makhachev went up against Jack Della Maddalena in a welterweight title fight at UFC 322 last month and defeated the Australian via a dominant unanimous decision. Soon after, Makhachev's manager backed Usman getting a title shot against the new welterweight king. 'The Nigerian Nightmare' has been calling for a title shot for quite some time and believes he deserves to fight Makhachev next.While many believe welterweight contenders like Ian Machado Garry, Carlos Prates, Shavkat Rakhmonov, and Michael Morales deserve a title shot before Usman, the reigning UFC welterweight king has a different opinion.In an interview with Red Corner MMA (translated from Russian), Makhachev claimed Usman would be his "hardest fight":"I said I wanted to fight Kamaru Usman next. Although the media doesn't believe in this fight, as I can see. But in my opinion, Usman would steamroll through these up-and-comers like Morales, Prates, the striker. Those guys haven't been checked yet. I think Usman would be the hardest fight for me, and in terms of media, we could build it up like a former champion, the most title defenses in my weight division. We could promote this fight and make it fun to watch."He added:"[Joaquin] Buckley was one of the contenders. Usman simply took him apart, and everybody has already forgotten about this guy. But if Buckley won, he would've been one hundred percent contender number one."When Kamaru Usman got honest about a potential Islam Makhachev clash at welterweightIn May, Kamaru Usman shared his take on a potential Islam Makhachev fight and outlined why the fight makes sense. Usman believes a fight against Makhachev would be a "blockbuster" clash and would make them both a lot of money.In an episode of the Pound 4 Pound podcast, Usman expressed his willingness to fight Makhachev and said:"Obviously, that's a blockbuster fight. Former pound-for-pound and current pound-for-pound champion. And that's something we'd have to talk about because I love those guys. Islam, Khabib [Nurmagomedov], I love 'em all... Remember what Mike Tyson said, Henry... He said it right, 'Friends make friends rich.' And hey, if that's the situation, then obviously I think Islam and I are mature enough to have a conversation about that. [Would I be open to it when the time comes?] I don't see why not."