Astori rejected an offer from Lazio to sign for the Giallorossi on-loan yesterday.
In a statement on their official website, the Sardinian side said: “The club can confirm that it has sold Davide Astori to AS Roma on a one-year loan with the right to buy.
“Cagliari would like to thank Astori for his professionalism, devotion and gratitude that he has shown right until the end.”
Roma will pay an initial €2m for the loan, and will have to splash out €5m to get Astori outright.
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