He has made an adjustment to his swing:
"I felt like I was having good at-bats, but I made little adjustments on my swing with my approach. It kind of slowed the game down, made 95 seem a little slower," the right-handed hitter said. "I did a little different stance, turned my shoulder towards the plate more [and] I focused on going the other way a little bit."
http://www.milb.com/news/article.jsp?ymd=20140724&content_id=86018404&fext=.jsp&vkey=news_milb
We'll see, but I do think he has the potential to hit for a decent average, as well he does seem to have a good approach and should have a good walk rate and OBP. Combine that with his near 80 speed on the scouting scale and plus glove at a premium position, and I think he has a chance to be an all-star. I'm a fan of the glove/speed/OBP combo. Even if he never hits for average, he'll be a dangerous 9 hole hitter, while if the bat comes around he has definite all-star potential.
Pentecost I like, but his lack of power is concerning, and his D is still very much a work in progress (particularly controlling the running game). He should hit for average though, but overall, I just feel like Turner brings more upside to the table. Pentecost to me is a one tool guy, and that tool is the toughest to project.