Since I'm not an ESPN Insider, here is the Peter Gammons article paraphrased by MLB Trade Rumors:
Peter Gammons reported back on Tuesday that the Yankees have already made a Johan Santana inquiry. The tidbit mentioned a cellphone conversation where apparently a Yankee exec asked who the team would need to part with aside from Chien-Ming Wang to acquire the Twins' ace.
Makes sense that the Yanks would place a call on this; Santana's the best pitcher in baseball and they're the Yankees. And the general vibe seems to be that the Twins are at least listening on Santana. Wang or Cano plus another premium prospect seems a reasonable bounty. The acquiring team may require a negotiating window. And technically, Santana could have the Yankees on his 12-team no trade list.
So the Yanks are willing to give up Wang as the centerpiece of a trade for twice Cy Young winner Johan Santana. Now, I'd be willing to do that but it mostly depends (for me, not necessarily the Yankees) on the players surrounding Wang (who wouldn't be a huge loss in my opinion). The following is the likely order of players that Minnesota would want included in a deal: Joba, Hughes, Cano, Melky, Kennedy, Tabata, AJax, Horne, Marquez, Betances, Montero, Abe Almonte, Heredia (followed in random order by Whelan, Gardner, Ohlendorf, AGon, McAllister, Kontos, Miranda, Norton). It's such a tough call but there's no way I'd trade Wang and Cano for Santana. Those guys are younger, cheaper and add more to a ballclub than Santana alone. Joba and Hughes have ace potential and again, are younger and cheaper than Santana (who will turn 29 in March). The rest of the guys I would strongly consider, but would be most willing to part with Alan Horne and Jeff Marquez.
Melky is just 23 and already one of the best centerfielders in the AL. He's also a switch-hitter with speed. His career line of .275/.340/.388 is far from stellar, but his D makes up for a lot of it: he had 4.6 wins above a replacement level CFer this year. I know his D will only improve so the question is how much (if at all) his offense will improve over the next few years. I think it will - .300/.350/.450 seems like a reasonable expectation. An .800 OPS from a great CFer is SO valuable that I'd be slightly against trading Wang and Melky for Johan (bear in mind that if the Yanks were granted a window to negotiate an extension with Santana then I might rethink some of these ideas).
Kennedy showed me a lot this year (even winning Minor League Pitcher of the Year!) - he didn't get a lot of time in the bigs (19 ip), but excelled, sporting a 1.89 era and 1.16 whip.
Betances, Montero, Almonte and Heredia are all under 20 with super potential. I wouldn't want to give any of them up (I love prospects) but to get Santana would relent.
All of this could be moot though if Minnesota gets off to a good start and considers themselves in the playoff race. With Francisco Liriano returning sometime in 2008, they could attempt a run at a title and maybe even re-sign Santana (they have a new stadium opening in 2010 so they'll have extra money and will want to fill seats).