This rumor was in circulation, but it is not true according to Jon Heyman of CBS Sports.
Cabrera of course was tied up in the infamous PED-scandal which ended his season with the Giants, and the team did not resign him in the offseason. They controversially kept him off their playoff roster despite the fact that he was eligible to come back.
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Cabrera of course left the Giants to sign with the Blue Jays this offseason, and it was for a modest and small amount. The rumor that he would turn down an offer like this lacks not only truth, but a basic logical purpose.
Not only did the team not offer him the deal, but according to Heyman they did not even discuss the contract offer. This is likely a case of Spring Training rumor-spreading, as opposed to actual concrete hearsay.
Cabrera was acquired by the Giants for pitcher Jonathan Sanchez, in what became infamous for the fact that Sanchez did not even make it through the season with Kansas City, while Cabrera helped the Giants tremendously for two years.