Edit: decided to go back and see how Martinez performed in 2011 and career-wise compared with this season.
Sources:
http://mlb.mlb.com/team/player.jsp?p...=1&season=2013 and
http://www.baseball-reference.com/pl...artivi01.shtml.
2011: 61-155, .394 AVG, .442 OBP, .548 SLG, .990 OPS.
2012: Did not play.
2013: 12-48, .250 AVG, .316 OBP, .375 SLG, .691 OPS.
Career: 388-1228, .316 AVG, .403 OBP, .463 SLG, .866 OPS.
As you can see, he's not doing very well whatsoever this season. Yes, the season's young (about 1/4 of the way through), and he still has time to "heat up", it'll take some significant hitting streaks to improve to anywhere near to what his normal career average is. Hopefully, he'll began producing soon, because where he is right now, he's more of a liability than help as a DH.