After injuries decimated the Twins' infield early in the 2008 season, Alexi Casilla got an undeserved call-up from Rochester, where he was hitting just .257/.344/.316 at the time. Though age could be named as a factor for his poor performance, the fact was that he had also proven himself unable to hit AAA pitching over the last two seasons. Luckily for Casilla, the Twins had so many injuries that they had to call him up as a last resort anyways, and luckily for the Twins, Casilla proved at first to be the answer at second base. He hit .313/.351/.424 through his first 62 games (273 PA), which would have ranked him in the top half of second basemen for OPS despite hitting in the AL's most pitcher friendly park of 2008. Unfortunately, he injured his finger on July 28th and went on the DL the next day under the assumption that he would miss the rest of the season. Surprisingly, though, Casilla returned to the lineup less than a month later, but hit only .225/.299/.289 over the final month and a half of the season. For someone with his track record, those numbers should not have been surprising, especially after rushing back from a finger injury that could have been affecting his performance. Nonetheless, it was pretty discouraging and disappointing after his impressive play from May to July. The one part of Casilla's play that remained notable was his plate discipline, as he maintained a 15:20 BB:K ratio even after coming back from his injury. In his minor league career, Casilla had always shown a good eye, so the continuation of this skill into the major leagues was good to see.
Thus far, 2009 has been an absolute disaster for Casilla. He ranks in the bottom 10 in MLB for basically every important statistic: OBP, SLG, OPS, wOBA, and value runs. Even his normally good BB:K ratio has suffered, with 2 walks and 9 strikeouts so far this season. He doesn't seem to be making good contact so far this season either, with a meager 10.2 LD% and a league-worst 50 IFFB%. This is most likely partially the result of his 58% jump in O-Swing% and 25% jump overall Swing%, which indicate that he's being much less selective at the plate. These greater number of swings have also come with a lower contact rate, down from 91% to 83% this year. Take his anemic offense in combination with his at best average defense (-0.3 UZR in 2008, -1.2 so far in 2009), and you have a pretty valueless player who has been worth -$2.4 million in 2009. Combined with his poor finish to the 2009 season and his minor league track record, these numbers show a disturbing trend, as it seems that the Casilla of late 2008 and 2009 is more likely the true player than the one who played so well from May to July last year. If that is the case, then clearly the Twins can not continue with Casilla at 2nd base, and fortunately they already have a better option in Brendan Harris. Harris has proven to be a near league average hitter with a career .325 wOBA, which is higher than even Casilla's supposed great season last year. Though his defense at second base has been sub-par, it's not nearly bad enough for Casilla to be playing over him.
In the end, Casilla should not be playing every day for the time being. I'm not sure if he has any options left, but if he does AAA is a good place for him. He never really deserved the call-up in the first place, and is showing why right now. Otherwise, a bench spot as a pinch runner and occasional starter at second and short is where he should be, with Harris getting the bulk of the starts at 2nd base. Casilla is still only 24 years old, so he has plenty of time to improve, but right now the Twins need to put the player who gives them the best opportunity to win on the field.