Kamaru Usman expressed a willingness to step in on short notice at UFC 310 but wasn’t clear about being contacted by UFC matchmakers.

Rakhmonov (18-0 MMA, 6-0 UFC) was scheduled to challenge welterweight champion Belal Muhammad (24-3 MMA, 15-3 UFC) in the Dec. 7 headliner at T-Mobile Arena in Las Vegas, but Muhammad withdrew due to ...