The Pirates are close to signing Jonathan Sanchez, reports Jon Heyman of CBS Sports. The deal is not yet finalized, but it is believed to a minor-league contract, per Rob Biertempfel of the Pittsburgh Tribune-Review.

Sanchez has been working on his mechanics all winter, but that is no guarantee of an improvement over his performance last season.

In 2012, he pitched 64⅔ innings and had an ERA of 8.07. He compiled those numbers for Kansas City and Colorado.

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He was acquired by the Royals before the 2012 season in exchange for Melky Cabrera, in what has become a much-bantered about trade.

Sanchez was at one time considered to be a top pitching prospect, and was a key part of the Giants' rotation for a couple of seasons. He even threw a no-hitter for the team in 2008.

The Pirates have been somewhat active in the lower-tier of the free-agent market this offseason, though their two-year deal with left-hander Francisco Liriano is still being renegotiated because of a fracture in his non-throwing arm suffered over the holidays.