Fernando Martinez went down on May 15th with a hamstring injury and has yet to return to duty. Before getting hurt, he was hitting .280/.314/.408 for Binghamton, with 9 doubles, a triple, 3 homers, 7 walks, and 39 strikeouts in 157 at-bats, 37 games. Given that he is just 19 years old and in Double-A, these are excellent numbers of course.
The sample size is small enough that a detailed analysis wouldn't mean too much. However the concerns about Martinez raised pre-season still remain intact. His plate discipline is poor right now, and in fact has worsened some this year with a higher strikeout rate. Again, given the sample size I wouldn't make too much of that at this stage.
This post is turning out to be a lot less interesting than I expected it to be...basically, nothing has changed here...he's extremely young for the level and the fact that he can hold his own against Double-A competition despite his youth and his poor plate discipline gives him immense potential. But the shape that potential may take remains very unclear to me. I could see him becoming a star or superstar, but I also think it's entirely possible that he could remain at his current level of performance for a long time, or perhaps improve only slightly.
In a way, it would be easier to get a read on what his future could look like if he was playing against competition closer to his own age group. If he was in A-ball right now, he'd probably be hitting something like .330/.365/.465....that would make Martinez's performance about equivalent of what Jayson Heyward is doing right now in the Sally League (.332/.385/.504).
Of course such "reverse MLEs" are problematic. The point remains that Martinez is an outstanding prospect and has lots of time to remedy his flaws. I have compared him to Bobby Abreu before, though I don't think Martinez will show that kind of plate discipline even at his peak. Let's see...how about a Garrett Anderson floor if the plate discipline is mediocre-to-poor, Harold Baines (not longevity-wise, but in terms of seasonal production) as a midpoint expectation if he develops decent but not great discipline, and a Bobby Abreu best-case if it develops to maximal potential?
CLARIFICATION: What I mean by the Garret Anderson comp is if Martinez does develop into a star of some kind, it could look like that, a guy who hits well despite mediocre discipline. It's entirely possible that he doesn't develop into a regular at all and becomes a fourth outfielder or something.