According to Jon Heyman, Brian Cashman is apparently willing to "talk about just about anyone in [a] trade, and while it's a long shot, that apparently even includes star closer Andrew Miller."
In his first season with New York, Miller posted a K/9 of 14.59, a HR/9 of 0.73, and an ERA of 1.90. He was unarguably excellent, and with three years left on his contract, he wouldn't be cheap.
Andrew Miller obviously wouldn't come cheap. Yanks would seek ace type or haul in return, someone like Stephen strasburg.— Jon Heyman (@JonHeymanCBS) November 9, 2015
While the Yankees appear to want an ace, trading Miller to acquire one would be an odd way to go about it. He was one of the best relievers in baseball, and with a yearly salary of just $9 million, he's extraordinary affordable.
Heyman also notes that Stephen Strasburg could be the type of pitcher that the Yankees want to target. A deal with the Nationals might make perfect sense, as Mike Rizzo could include Drew Storen in the deal, and replace him with Miller, which would likely alleviate some of the tension in the bullpen.
The Nationals wouldn't be the only team interested however, as Heyman writes that the "Tigers, Diamondbacks, Red Sox, Astros, and Blue Jays are among teams looking at closers."