Double-A Portland: Manuel Margot, CF
Margot was promoted to Double-A Portland after something of an up-and-down start to the season with High-A Salem. He started out well, but was a bit too impatient, something pitchers made him pay for in May. Before his promotion came in late-June, though, he had recovered, hitting .316/.342/.474 over that month's 18 games and 80 plate appearances. He's done much of the same since coming to Portland, with a line of .293/.349/.448 to go with five steals in six attempts.
Maybe most important is that Margot doesn't seem to be rushing his plate appearances. He has struck out 10 times in 63 trips to the plate, and that's actually something of a good sign: Margot occasionally goes on runs where he avoids striking out but also avoids walking, and likely loses his best chance at a hit somewhere in between. That hasn't been the case so far, and while he's probably never going to walk a ton, giving himself the occasional chance to do so will go a long way.
Not only will it get him on base more often, but it should give him a better chance of discovering that power stroke that many scouts believe is there. Remember, Margot is still just 20 years old, and won't turn 21 until the MLB season is almost over, never mind the shorter minor-league one. He's a quality baserunner who is also going to be at least an above-average defender in center, and even if the power doesn't ever come, there is value in his bat.
Be patient with Margot, because there should be an eventual correction in his performance he'll have to adjust to here, too, just as there was at Salem. Be excited, though, because Margot is either going to be an important part of Boston's future, or he's the kind of trade piece who can bring that kind of player to the Sox.
High-A Salem: Trey Ball, LHP
Trey ball still has work to do, but his performance finally seems to be coming around. At first, he was doing well to avoid giving up runs, but his strikeout and walk numbers were still ugly, and his overall production unsustainable. He has allowed one run or fewer in six of his last nine starts, though, and three runs or fewer in eight of them, and has finally started to put some separation between his strikeouts and walks over the last five of those, with 19 punch outs against 10 free passes in 26-2/3 innings.
It's not perfect, but it's a sign that Ball -- who is designated as in his age-21 season even though he turned 21 just 10 days ago -- is making legitimate, tangible progress for the first time since he was drafted seventh-overall in 2013. It was always known there would be a transition period for the lefty, who was a two-way player in high school, so seeing it take a few seasons isn't a surprise. If you think he took too long to get going, it's worth remembering that he's only nine days older than Andrew Benintendi, an outfielder the Red Sox took seventh-overall in the MLB draft one month ago. Benintendi, by the way, qualifies as an age-20 player this season because his birthday came days after the cutoff instead of before -- see how viewing Ball exclusively through that window can be a bit unfair to him?
Ball looks to be on the right track now, and while it seems like it's taken forever, the only thing that really matters is if he can keep on progressing down it successfully. We need more time to see if that's the case, but so far, so good this summer.
Low-A Greenville: Javier Guerra, SS
The one real concern with Guerra to this point in the season is his performance against left-handed pitching. While the lefty Guerra has batted .304/.360/.497 against opposite-handed opponents, southpaws have limited him to .224/.268/.395, not harming his power, but cutting into his walks and hits. It's also a sample of 86 plate appearances, so maybe don't get too worked up over it, but it is something to keep an eye on. It's not like Guerra is going to be facing easier pitching the higher in the system he gets.
It is worth the reminder that Guerra is all of 19 years old, however, and has exactly 11 plate appearances against pitchers who are younger than he is. His OPS is 106 points higher than that of your average Sally League player, and he's two years younger than they are. There is a lot to like about his campaign, especially the fact he's hitting at all since he was considered a defense-first guy coming into the season, so while he has much to work on, you can still sit back and admire what he's managed.
Short-season Lowell: Austin Rei, C
Austin Rei was drafted in the third round of the 2015 MLB Draft by the Red Sox, and he made his professional debut on Monday night for the short-season Lowell Spinners. He went 0-for-3 with a strikeout, so he didn't have the same immediate impact that Andrew Benintendi did, but in the long run, the early performances of both players doesn't matter.
The 81st pick in the draft -- and Boston's second selection overall -- was something of a sleeper who Baseball America's John Manuel believes is better than some of the players who went in the first two rounds. He was the 68th-ranked player on their top-500, and while a torn thumb ligament kept him from catching when he first returned from the injury, his skills behind the plate are intriguing, too, thanks to his strong arm and his hands. It'll take some time to know just what the Red Sox have in Rei, but he could be a pretty good player by the time we do know.
GCL Red Sox: Kevin Steen, RHP
Kevin Steen, drafted in the ninth round last summer, is still just 18 years old. The Sox popped him in the Gulf Coast League once again rather than jump him to Lowell, which makes sense given he was limited to just six innings last year in the pros after taking some time to sign. Things have gone well so far, with Steen now up to 18 career innings at the level with 15 strikeouts against five walks and just three runs allowed, none this season.
The right-hander could be a starter, but he's so far from the majors at this point that figuring out what his role is now is pointless. He's loaded with projection and could just as easily be nothing as he could be a big-league arm, so for now, the key things are improving his secondaries, making his delivery repeatable, and figuring out how to throw a quality strike on command. He's got the time to do it, and might even get bumped to Lowell before this season is out, but there is no rush on this young project.