Billy Butler continues to struggle. (USATSI)
Billy Butler continues to struggle. (USATSI)

Royals designated hitter Billy Butler has caused plenty of headaches for Fantasy owners this season. Through 42 games, he's hit just .227/.283/.287 with one home run. Given his track record, it's tough to expect those numbers to continue over the entire season. While there's hope for Butler's overall line to rise, he's probably not going to churn out his vintage stats.

Butler's lack of pop has been fairly concerning for a while now. After clubbing 29 home runs in 2012, Butler saw his total drop to just 15 in 2013. That may have caused some Fantasy owners to hold out hope for a rebound, but his batted ball rates don't suggest the power will return. 

Butler is hitting a career-high 57 percent of his balls on the ground this year. That puts him in similar company with Dee Gordon and Adeiny Hechavarria. This is a fairly obvious point, but he's not going to hit home runs by pounding the ball into the ground. Not surprisingly, Butler's uptick in ground ball rate began last season, as he put 53.1 percent of balls on the ground. That helps explain his low home run total.

Now, it's certainly possible that Butler's just going through a bad stretch. In fact, his low 3.7 percent home run rate suggests more power will come. Even with that being the case, he's not a candidate who will suddenly slug 20+ homers again. Ground ball rate stabilizes pretty quickly compared to other stats, according to Baseball Prospectus' Russell A. Carleton. What that means is, even though Butler could turn things around, he's unlikely to see his batted ball data change significantly moving forward. Even if you don't want to buy into the theories in that article, Butler's history of declining batted ball rates isn't all that encouraging. 

Butler's not going to draw much in a potential trade at this time, but there's a chance Fantasy owners can swap their underperforming player for another underperforming player. As of right now, Butler seems unlikely to reclaim his former glory. If he can be moved for a more interesting part, now is the time to do it. 

*Gentleman's tip of the cap to Big Hurc for the post idea.