Saul 'Canelo' Alvarez would not rule out a trilogy with his rival Gennadiy Golovkin – but warned "it is not a challenge for me".
Canelo became a four-weight world champion by emphatically knocking out Sergey Kovalev on Saturday night to pick up the WBO light-heavyweight belt.
But he still owns gold at middleweight, where he fought two classic encounters with Golovkin. The first was a draw and the second was won by Canelo but Golovkin disputes both decisions and has always called for a third fight.
"It's not a challenge for me. We fought 24 rounds and I beat him," Canelo said post-fight. "But if it represents business, then why not?"
Golovkin recently won the IBF title so both men would enter the fight, likely on Cinco de Mayo weekend in May 2020, with middleweight world titles.
Other options at middleweight would include Demetrius Andrade, the WBO champion, while super-middleweight champions Billy Joe Saunders and Callum Smith also lurk.
Canelo would not confirm if he plans to have a second fight at light-heavyweight, where the other champions are Artur Beterbiev and Dmitry Bivol.
Those champions, who are both Russian, were called out by their compatriot Kovalev who insisted he would not retire despite a fourth career defeat.
The 36-year-old said: "I'll be back - I know I can unify. But nobody wants to fight me in my division."