Bernard Hopkins has stated that Anthony Joshua must beat the likes of Deontay Wilder from the United States to truly become the face of global heavyweight boxing.
The former two-weight champion believes that the Brit has all the ingredients required to reach the top, but still has much to prove in order to endear himself to the fans in America.
Asked whether Joshua is already a heavyweight 'superstar', Hopkins replied: "No. Will he be? I believe so.
"What he needs to do is to come to America and fight the top champions, if they are willing to fight. The top contenders, if they are willing to fight.
"He has the ingredients, he definitely has the personality and he can flat out fight. A superstar in the making. He is in the position to become the face of the heavyweight division. Right now, I can't give him that."
Joshua has previously stated his intention to unify the heavyweight division, playing with the idea of facing WBC champion Wilder with a potential fight between the pair having been touted for 2018.
Similar to the Brit, Wilder is also undefeated since turning professional in 2008, but Hopkins believes that Joshua would have the upper hand if they were to face next year.
"I think he [Joshua] is more savvy, the veteran - even though he is not a veteran," said Hopkins.
"He has experience and he'll fight with great confidence. I have to give the edge to him, I really do.
"Not a big edge, but I have to give it to Joshua based on, not just his size - but that's a factor, but the way he believes in himself. Look how he fights."
Joshua will return to the ring after six months following his victory over Ukrainian legend Wladimir Klitschko.
The promising British boxer will now face Kubrat Pulev in a mandatory defense of his WBA, IBF, and IBO heavyweight titles on October 28 in Cardiff.