Former world champion Joseph Parker believes IBF, WBO, WBA, IBO heavyweight king Anthony Joshua is intentionally delaying a potential unification with WBC champion Deontay Wilder.

Back in March, Parker became the first boxer to go the full distance with Joshua in their unification bout. Parker was never hurt during the contest and lost a twelve round unanimous decision.

The camps for Joshua and Wilder were in talks for several months for a fall showdown.

Now Joshua is going to make a mandatory world title defense against Alexander Povetkin in September.

Parker is shocked that Joshua stretched out the discussions with Wilder until this point - and rejected a guarantee of $50 million to face Wilder in the United States.

"I'm surprised," Parker told Andrew Gourdie and Jim Kayes on Sunday Sport.

"After the fight with me he called [Deontay] Wilder out, but it seems to me he keeps changing his tone despite Wilder clearly wanting that fight. He [Wilder] wants to unify the division. I speak to him often and can really sense that passion he has to be undisputed champion.

"Joshua wants to unify too but I don't think he thinks he is ready for Wilder. He [Joshua] wants to take that fight at the right time for him."

Parker has a lot of respect for Wilder and believes he's the biggest puncher in the entire division. He says Joshua never hurt him once in their entire twelve round bout.

When factoring everything, he's confident that Wilder will come out on top when he faces Joshua in the ring.

"Personally I think Deontay Wilder takes it. Even though he is wild by name and nature, he is loose, elusive and has power," Parker said.

"He has scary one-punch knockout power. I'd take him to win, but boxing is a funny game and I could be proven wrong."