The New York Yankees are the second worst team in the American League at scoring runs (hello Boston!).
The Yanks' 3.92 runs per game is actually below the National League average. So the Yankees are so bad, that they're worse than the average team that lets their pitcher hit.
And with that said, the Yankees were actually playing better baseball before they parted ways with Alfonso Soriano and Brian Roberts. While the Yankee offense for the year has played about 10% below league average (park adjusted according to wRC+), in August that has actually fallen to 20% below average, and the smoking gun is that their on-base percentage has collapsed from an anemic .310 in the first half to a truly offensive (the other kind) .280 since the trade deadline.
Recent additions Stephen Drew (.224) and Martin Prado (.266) certainly carry a fair share of blame, and with 3 homers and 8 doubles between them, it's not as though they're slugging their way to relevancy. Maybe there's a reason they were available so cheaply?
The team's .272 BABIP suggests that a combination of weak contact and bad luck has been costly of late. The time Brian McCann lost to a concussion has actually helped because Francisco Cervelli has led the team in August with a .296/.367/.519 line. Ichiro filling in for Carlos Beltran has been nearly as good at .345/.355/.414. Derek Jeter's latest slump (.225/.247/.296 in August) will surely be papered over by the Intangible Farewell Tour (and maybe that's ok).
All of this has small sample size stitched into it, but we're not talking about expecting Cervelli to slug .500 for his career or for Ichiro to turn back the clock in 2015. If we want the Yankees to win a playoff spot, they need to play their most efficient lineup, and right now that might mean Cervelli behind the plate for more than just Brandon McCarthy's starts. It might mean seeing Derek Jeter getting a lot more "rest" and accepting the better glove of Drew or Brendan Ryan.
The Yankees haven't run out of time yet, but they have to figure out how to win with the team they have.