8:54pm: Rob Biertempfel of the Pittsburgh Tribune-Review confirms that the deal is close and adds that it would be a minor league contract (Twitter link).
Sanchez, 30, was traded from the Giants to the Royals for Melky Cabrera last offseason, but the trade wound up being a lopsided one. Sanchez pitched to a 7.76 ERA and walked 44 batters in 53 1/3 innings for the Royals before being designated for assignment. The Royals flipped him to the Rockies for Jeremy Guthrie, who had endured similar struggles in Colorado. He didn't fare much better there, however, as he allowed 12 earned runs and walked nine in just 11 1/3 innings.
Sanchez makes sense as a low-risk investment, however, given his success from 2009-11. The southpaw compiled a 3.75 ERA, 9.5 K/9 and 4.9 BB/9 in 458 innings during that time. Sanchez isn't entirely dissimilar from Francisco Liriano, with whom the Pirates are still attempting to finalize a deal. Both lefties have swing-and-miss stuff but struggle due to erratic command.