I believe Brett Anderson said it best

Gio was one of the hottest players discussed at the winter meetings this past week. According to sources, out of all 30 teams in baseball, more teams than not at least asked about the left hander.
There are nine teams we know for sure that have expressed interest in Gonzalez; the Rangers, Jays, Tigers, Nationals, Marlins (shocking), Yankees, Phillies, Reds and Diamondbacks. Billy Beane is said to be asking for a “Dan Haren type deal”, which brought Arizona’s top prospects Brett Anderson, Carlos Gonzalez and Chris Carter to Oakland.
Gio is a Miami area native and has expressed interest being traded to the Marlins or Yankees if he happens to be traded. I do believe these two teams would be the front runners in landing him because they have exactly what the A’s are looking for, it just depends on what they are willing to give up. It’s believed that Beane is asking for a package built around Logan Morrison from the Marlins, but they are more willing to part with Gaby Sanchez than Morrison. If Beane wants a Dan Haren type package in return, Gaby Sanchez will not get this done. From the Yankees we hear Beane is asking for catcher Jesus Montero AND pitchers Manny Banuelos or Dellin Betances, the asking price is a bit steep for the Yankees and they have supposedly said “no” on this offer.
I personally don’t think the Phillies and Tigers have anything worth trading for so those talks will probably die down soon, if they haven’t already. I would like to see one of two things, Beane keeps Gio around and signs him to a Cahill-like extension, or we trade Gio to the Yankees for a package that revolves around Montero. It’s hard to say where he will land at this point with so many teams being involved in rumors.