Paris Saint-Germain and Manchester City have also been linked with the Argentine, who is under contract in Italy until 2014.
But Lazio president Claudio Lotito has previously insisted that there have been no offers for the former Birmingham man.
And he maintains that Zarate will not be allowed to leave for anything less than Lazio's valuation.
Lotito is quoted as saying in the Daily Mirror: "Zarate is not on the market, but it is clear that if a top offer was to arrive it would be considered."
Source: Team Talk
Source: Team Talk