Kamaru Usman believes UFC champion Dricus Du Plessis still has some work to do before moving up a division. Du Plessis (23-2 MMA, 9-0 UFC)  retained his middleweight title by defeating Sean Strickland (29-7 MMA, 16-7 UFC) a second time in Saturday’s UFC 312 headliner at Qudos Bank Arena in Sydney. Du Plessis called out light heavyweight champion Alex Pereira after the fight but later revealed he wants to fight Khamzat Chimaev first . Many view Chimaev as Du Plessis’ toughest fight at 185 pounds, but Usman believes Nassourdine Imavov (16-4 MMA, 8-2 UFC), who’s coming off a knockout win over Israel Adesanya at UFC Fight Night 250 , can also pose problems. “If he (Du Plessis) fought a guy like Nassourdine Imavov the way that he fought Sean Strickland last night, I don’t like that fight for DDP,” Usman said on his “Pound 4 Pound” podcast with Henry Cejudo. “I don’t like it