The Italy international is poised to complete a 20 million euro move to Anfield, having said goodbye to his AC Milan teammates earlier this week.
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Balotelli's career has been plagued by controversial incidents, leading to reports that he has had to agree to a behavior clause with the Reds, and Raiola has sounded a warning to the striker that this is his last chance to let his talent do the talking.
"He is not ready to be a leader," he told Corrierre della Sera. "Liverpool have [Steven] Gerrard. Mario will be protected there and will be at his best.
"Now it is up to him. Another flop is not advisable, his age is not an excuse."
Raiola says he has been working on engineering a move for Balotelli for three months, and says he was "always against" the striker returning to Italy following his spell at Manchester City.
"The negotiations have been going on for three months. It's not exactly a scoop," he added. "Liverpool have always been the only English club who negotiated for Mario. I never lied to the media. Three days ago there was talk of Liverpool, but no offer. The truth is I've been working on Mario for months. The time had come to divorce from Milan.
"There wasn't any row, incident or change. It's not true that the rapport broke down with Milan. I was always against bringing Mario back to Italy. The pressure, the expectation, the media… playing in Italy is much tougher for him than abroad.
"He insisted that he wanted to go from Manchester City to Milan and between client and agent, the client always decides."