‘Super Mario’ has fallen from grace since winning the Premier league title with Manchester City five years ago, becoming an un-wanted liability at current club Liverpool after failing to earn a permanent deal while on loan at Italian giants AC Milan last season, netting just three times in 23 appearances.
And former Azzurri teammate Pirlo admits he’s been left disappointed by the 25-year-old, from whom he expected much more.
"He frustrates me, but I do have so much affection for Mario," Pirlo told the Mirror.
"He is infectious to be around. When I used to see him walk into training for Italy, he would have this big smile on his face - and I would just burst out laughing - and start wondering what is he thinking, what is he up to?
"Mario should not just be a character the media write about for good stories. We shouldn’t forget what a special player he is.
"I have played with some of the best strikers, and I can tell you Mario has all the attributes to be one of the best strikers in the world.
"By now I thought that is where he would be, that is where he should be. He has no more time to waste."
Pirlo advised the talented forward to think carefully about his next move, and hopes he will not follow the money to China.
"He has played for so many big clubs, it's easy to forget he's only 25,” the New York City FC playmaker said.
"He still has time to make it at the very top. [But] He needs to pick his next club carefully.
"I have read things about him and China. With all respect to their league, Mario should not be going there yet.
"If he has two or three good seasons at his next club, he will still only be 28 and could join one of the top clubs in Europe.
"I don't have any advice for him anymore, he knows the qualities that he has. From this point, it's up to Mario."