Lennox Lewis believes that new IBF heavyweight champion Anthony Joshua is not yet ready to face WBA and WBO title holder Tyson Fury.
After Joshua's two-round demolition of Charles Martin to win the belt at the O2 Arena on Saturday night in his 16th professional fight, Britain now has two world heavyweight champions, but Lewis says Joshua remains a "a work in progress" at present.
Fury won the WBA, WBO and IBF titles from Wladimir Klitschko back in November, but was stripped of the latter - that Joshua won - after failing to agree to fight his mandatory challenger at the time, Vyacheslav Glazkov.
The 27-year-old Fury will instead take on Klitschko in a rematch in Manchester on 9 July, the same night as Joshua's first defence of his belt in London.
Retired former British world heavyweight champion Lewis wrote on Twitter: "Great showing by AJ 2 to lift IBF belt from this muppet, but he's still got a lot 2 learn and he knows he has 2 to do it as a title holder.
"It's definitely not time to talk about AJ and Fury or Haye. He's coming along well, but this fight was just a good opportunity to grab a belt.
"I regard @Tyson_Fury as top of the heap right now. IBF shouldn't have stripped him and that's why the opportunity existed.
"I definitely can't blame AJ and his team for jumping into the opportunity tho. Made sense.
"Let @anthonyfjoshua have his moment. It's great 4 British boxing and the fans. But also know that he is still a work in progress."
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