Low-A Greenville: Javier Guerra, SS
Javier Guerra was supposed to be a defense-first shortstop, but right now, he's a 19-year-old slugging over .500 in his first year of full-season ball. He might still end up being primarily a glove guy, but it's hard to ignore how well things are going at the plate for the teenage Panamanian. It's come a bit out of nowhere, too, as he didn't walk or hit for power in his first two seasons as a pro. Granted, they were in the Dominican Summer and Gulf Coast leagues, but still, you'd think there would be a hint of this kind of production buried somewhere within his past.
The strikeout rate -- Guerra is whiffing 30 percent of the time -- is worrisome, even for a 19-year-old. However, if he's drawing walks and he's hitting for power, the strikeouts can be forgiven to a degree. If Guerra can cut down on the strikeouts a bit once he realizes when it's right to be aggressive and when the proper call is patience, then he could really be something offensively.
Let's not get to excited, though. Guerra isn't like Rafael Devers or what Xander Bogaerts was back when he was a teenager, in that it was expected he would hit. And putting up eye-popping lines against high minors competition is a whole lot different than doing so against pitchers in the low minors, even for a player with youth on his side like Guerra. If he keeps on mashing, though, then it's going to be hard to ignore that he's succeeding at the plate, even when (and especially because) no one expected it.
Triple-A Pawtucket: Henry Owens, LHP
Henry Owens sure is walking batters. Yeah, it hasn't been that many innings at Triple-A, and yes, he's trying to figure out how to work a slider into his repertoire, but an equal number of walks and strikeouts is concerning for the 22-year-old, since the hope was that he'd be ready to take a rotation spot in Boston in 2016. Is he going to be able to fill that rotation hole? That depends entirely on whether or not he can get back to being the Owens that he was that got us all so excited in the first place.
Please don't take that to mean that the feeling around here is he won't get back on track -- Owens is either the top pitching prospect or the second-best pitching prospect in the system, depending on what you think of Eduardo Rodriguez. It's just that you knew Owens would eventually face a challenge, and that the challenge could likely come in Triple-A against International League batters, and hey, Owens so far hasn't been up to said challenge. Given more time, Owens should be able to solve these problems and get his control working for him, as he did a couple of years ago when he jumped from Low-A to High-A, but things might be a bit ugly in the meantime.
Double-A Portland: Justin Haley, RHP
Haley did fine enough in his introduction to Double-A in 2014, but this season has been awful. He's walking more batters than he's striking out, he's thrown fewer than 20 innings in six starts, and he's hit four batters while throwing another six wild pitches. The big question with Haley coming into the year was whether or not he'd be able to continue looking like a potential big-league starter, and early returns suggest that his career is in the bullpen. It's still early enough that this could change, and we've seen Haley rebound from absurdly, embarrassingly lofty walks totals before, but it will be harder to believe in him the longer he struggles.
He had a break in between his last two starts, pitching on May 2 and then not again until May 12, and it seemed to do him some good.He struck out just one batter and walked a pair, but lasted five innings for the first time all season and limited the Trenton Thunder to just two runs and six hits. He also threw just 72 pitches, so if he had been pulled due to pitch count instead of how many innings he had put in, he might have lasted a bit longer and looked much more like the Haley that got him put into prospect updates like this one in the first place. It's too soon to give up on Haley, but he doesn't have a whole lot of room for failure in his profile, so he needs to recover sooner than later to still be considered a potential starter.
High-A Salem: Wendell Rijo, 2B
There are things to dislike about Wendell Rijo's season: his on-base percentage is .293, and he's walked just five times in 76 plate appearances. There are also things to like about how Rijo's 2015 has gone, as he's slugging .478 and has 11 extra-base hits in his 20 games. Those walks stand out, though, because they remind you that Rijo is just 19 and still raw in terms of his approach, and the fact he's struck out 24 percent of the time doesn't help you forget that.
There is no rush for Rijo because of his youth, so if he has to spend another season at High-A to figure things out, he'll still only be 20 years old when he's doing it. But let's remember, too, that minor-league seasons are all about development more than what the stats look like at the end of the season, so while Rijo is doing some things right now, by the end of the year, he could be doing just about everything right. It'll take learning some proper patience to get there, so don't expect it, necessarily, but it's certainly a possible future for Rijo.
[Editor's Note: Please excuse any statistics that aren't accurate: this was written on Thursday, prior to the completion of that day's games.]