The Manchester United superstar visited AJ ahead of the heavyweight’s champ’s successful title defence against Carlos Takam.
And the Swedish legend, 36, landed a verbal body blow with his unexpected career advice.
Joshua said: “Zlatan loves his boxing and his mindset is phenomenal but he picked me up on something I said after my fight with Wladimir Klitschko earlier in the year.
“He pointed out that I’d said ‘I’m not perfect, but I’m trying’. Then he said ‘No, no no. What you must is say is ‘I am perfect and I’m not trying!’”
Ibra, who is recovering from a serious knee injury, was ringside as AJ stopped Takam in ten brutal rounds at Cardiff’s Principality Stadium.
And he declared: “He is not as good at boxing as I am at football… but he’s getting there.
“He’s a knockout artist and his personality is good because he is perfect and he is not trying.
“There are positive vibes all around him, he has good energy and expresses himself very well.
“That’s why everyone loves him. It’s why he’s the people champion.”