Hernandez, who pitched under the name Fausto Carmona through 2011, threw 151 innings for the Rays last year -- finishing with a 4.89 ERA. He will serve as a back-end starter for Philadelphia, presumably sliding in behind Cliff Lee, Cole Hamels, Kyle Kendrick, and Cuban defector Miguel Alfredo Gonzalez. His solid ground ball percentage could be an asset in the pitcher-friendly confines of Citizen's Bank Park, but he's struggled with the long ball recently. Hernandez allowed homers on 21 percent of his fly balls in 2013, despite spending his home games in a pitcher's haven.
After the announcement of Roy Halladay's retirement and rumors that the Phillies might entertain a trade for Lee or Hamels, the signing of Hernandez gives them an arm to lean on to soak up innings, regardless of whether the rotation stays in place from here on out or not.
In his time with the Rays, Hernandez wasn't exceptional -- in fact, he pitched poorly -- but he reestablished himself enough to earn a major-league contract at the winter meetings. After the bogus identity debacle that led to his Cleveland exit in 2012, that's a step forward.
According to Baseball Reference's reckoning, Hernandez was a sub-replacement-level pitcher last year, so the fact he can throw innings isn't automatically a positive for the Phillies. As far as inexpensive depth or temporary options go, though, you could do worse.