Diaz to Pittsburgh

In a deal that resembles the Ryan Church move from last season, the Pirates added outfielder Matt Diaz on a two year contract Tuesday night. With Lastings Milledge non-tendered, the Pirates had room on their roster, if not in their starting lineup, for another outfielder. Diaz will see his playing time in the corner outfield, whether it comes as a starter, or, more likely, in a platoon situation.

Although contract details are unknown as of this writing, it’s difficult to imagine that Diaz brought in much of a haul for his services. Over the past five seasons, Diaz’s performance has fluctuated wildly. Since 2006, Diaz has posted wRC+ marks of 115, 128, 51, 139, and 100, and, similarly, WARs of 2.2, 3.0, -0.8, 2.6, and 0.6. Part of this is merely the nature of his part-time role with the Braves; another part is likely due to his wild platoon splits. In 798 plate appearances vs. left handed pitchers and 849 against right handed pitchers, the right handed Diaz holds career wRC+ marks of 139 against lefties and only 90 against righties. Even accounting for the necessary regression, Diaz still has a markedly larger than average platoon split.

Diaz hasn’t measured well in the outfield over the past two seasons, and the Fans Scouting Report agrees with UZR and DRS, grading him as a -4 corner OF from 2009-2010. As such, his defense doesn’t allow managers to ignore his deficiencies against right handed hitters, drastically limiting his usefulness. At 33, Diaz’s glove has nowhere to go but down. This limited defensive ability likely makes Diaz a slightly below average player overall.

Due to the large platoon splits, Diaz isn’t exactly the same player as Church. But the endgame here seems similar: the Pirates will likely look to build Diaz’s value in the outfield as the rest of their team develops, hoping to flip him for a useful piece in their rebuilding plan. Even though Church was among the worst NL hitters before the trade deadline last year, the Pirates still managed to pry Chris Snyder from the Diamondbacks in exchange for Church and two players who have already managed to work their way off the Arizona roster in D.J. Carrasco and Bobby Crosby.

There’s no reason to believe that Diaz will fail as miserably as Church did in Pittsburgh. Given the amount of interest shown for Diaz by teams ranging from the Diamondbacks and Royals to the Red Sox and Yankees, the Pirates shouldn’t have any problem finding a suitor come July. As long as the contract is representative of Diaz’s role as a platoon outfielder – and nothing Neal Huntington has done in recent times suggests it won’t be – Diaz should fit the purposes of the front office perfectly.