8:37PM: The Yankees are "watching everyone, focused on no one," a source tells Marc Carig of the Star-Ledger (via Twitter).
2:23PM: George A. King III of the New York Post lists both Carlos Zambrano and Ryan Dempster as two pitchers of potential interest to the Yankees (which we also heard yesterday), but soon after notes that the Yankees would prefer to add a left-handed starter, and that they also prefer players who are only signed through 2011.
King names Wandy Rodriguez as the best available southpaw starter, though he's anything but a rental; his contract is guaranteed through 2013 with an option for 2014. Dempster better fits the criteria of a rental player; he has a $14MM player option for 2012, but after a disastrous start owns a 3.21 ERA with 53 strikeouts in 56 innings of work since May 1. If he continues to pitch that well through season's end, he can likely find more money on the free agent market. Dempster also has full no-trade protection, making him a difficult target.
Left-handed starters whose contracts expire following the 2011 season include Paul Maholm, Bruce Chen, Jeff Francis, and Zach Duke. Of the four, only Maholm is currently pitching well enough to be considered an upgrade. Mark Buehrle is also a free agent following 2011, but a clause in his contract states that he will receive an extra year at $15MM if he's traded this season.
Maholm earns just $5.75MM this year and has a $750K buyout on his $9.75MM option for 2012. To date, he's compiled a strong 3.12 ERA that's supported fairly well by his 3.53 FIP and 3.89 xFIP. Chen has been solid in 42 2/3 innings for the Royals, but is currently rehabbing from a lat muscle injury. Those names, of course, are pure speculation based on the Yanks' stated desires.
New York is currently sixth in the American League in starters' ERA with a mark of 3.89, but that's been largely supported by surprising performances from Freddy Garcia and Bartolo Colon, who was recently put on the 15-day disabled list. As King points out, the club expects Phil Hughes to return at some point as well. He's set for a rehab start tomorrow.