The Brewers' Asking Price For Corey Hart: MLB Rumors - MLBTradeRumors.com: "The Brewers asked the Giants for Jonathan Sanchez or Madison Bumgarner in exchange for Corey Hart, according to Henry Schulman of the San Francisco Chronicle (Twitter link). Giants GM Brian Sabean is understandably hesitant to deal either pitcher."
Jonathan Sanchez is going to be a 2nd year arbitration player after a $2.1MM salary following his 1st one. Corey hart will be a 3rd year arbitration player and cost more.
Given Sanchez is no longer young and no longer super cheap, his struggles with control seem to be permanent. I say the Giants should pull the trigger.