Anthony Joshua insists he is ready to "rock and roll" with Oleksandr Usyk, if a WBO title defence is enforced next after his points win over Andy Ruiz Jr.
Britain's heavyweight star regained the WBO, WBA 'super' and IBF titles following a masterful points victory over Ruiz Jr in Saudi Arabia on Saturday night, and WBO president Paco Valcárcel was quick to tweet that mandatory challenger Usyk must receive a title shot within 180 days.
The Ukrainian pound-for-pound star watched from ringside at the Diriyah Arena and Joshua welcomed a showdown with Usyk, who has joined the top division after becoming undisputed cruiserweight champion.
"In 180 days? Let's rock and roll mate," said Joshua at his post-fight press conference, when asked about Usyk.
"No problem," he added.
Ruiz Jr called for a third fight, but promoter Eddie Hearn confirmed Joshua will fulfil his title obligations, with the IBF also likely to order a title defence against their mandatory challenger Kubrat Pulev.
"There's an IBF mandatory, there's a WBO mandatory," said Hearn. "Tonight's about celebrating the victory. His first mandatory was Kubrat Pulev, he pulled out, he faced Carlos Takam on a week's notice.
"His WBA mandatory was Alexander Povetkin. Nobody wanted to fight Alexander Povetkin at the time, he took care of that mandatory as well.
"Kubrat Pulev is the IBF mandatory, Oleksandr Usyk is the WBO mandatory, and I see him wanting to take both of those fights as well.
"We'll have to speak to the governing bodies, see who goes first, and then deal with that. Anthony will have a nice Christmas and a holiday. We'll work behind the scenes."
Usyk could be made to wait for his guaranteed WBO title fight as the IBF have suggested their mandatory must come first for Joshua and fellow Brit Derek Chisora has been holding talks over a fight with the Olympic gold medallist.
Joshua remains eager for an undisputed world title fight with Deontay Wilder, but believes the American would have been hoping for a victory by Ruiz Jr, who is under the same promotional company as the WBC champion.
"Oleksandr Usyk, Pulev, Ruiz, I don't want to mention the other guy's name, you know who they are, but when they're ready," said Joshua, who did not rule out another fight with Ruiz Jr.
"I've fought a lot of great names on my record. I've beaten some good names as well and I'm looking forward to taking on more challenges. Andy is still on that list, because I think we make for good music. He's a good dancing partner.
When the opportunity presents itself to become undisputed heavyweight champion of the world, you know me by now, I'll definitely step up and take the challenge.
"I'm sure PBC were desperately rooting for Andy to win, but we came and put a little spanner in their works. We'll see what happens. I'd love to unite the belts, but I think me chasing him, same as in the fights, if I'm chasing the right hand, I'm chasing the right hook, it may come crashing down.
"I realise that chasing that fight wasn't playing into my benefit. I've just going to let the path take its course. I've got great people managing me. I've got a great team, and when the opportunity presents itself to become undisputed heavyweight champion of the world, you know me by now, I'll definitely step up and take the challenge."
Watch Ruiz v Joshua 2 repeats on Sunday, live on Sky Sports Box Office, from 8am and 2pm. Book it via your Sky remote or book it online here. Even if you aren't a Sky TV subscriber you can book and watch it here.