Simon Mercedes, RHP
Mercedes throws hard, can miss bats, and induces grounders. What's not to like about that? You probably shouldn't have asked that question. Mercedes doesn't have an effortless delivery, and he at times struggles with his release point, resulting in command issues that can come back to haunt him. His velocity dropped toward the end of 2013, which wouldn't be much of a problem except he threw just 63 innings at short-season Lowell.
Don't take this to mean Mercedes requires bashing or anything -- some realism just needs to be tossed into the analysis of a 22-year-old who can hit triple digits. He has a lot of potential, but there are a few obvious roadblocks he needs to get out of the way before we can think of him as anything but a future reliever. With his velocity, all he would need is either his bender or his change to shape up to be a high-quality reliever, since that role would take some of the edge off of those games where he just can't find his release point or command.
Justin Haley, RHP
Haley is off to a great start, which should come as no surprise given how well he pitched during the second half of 2013 for Low-A Greenville. He's currently punching out three times as many batters as he's walking has only given up one homer -- Haley allowed just 10 in 124 frames a year ago -- and has once again kept hits to a minimum. That last bit won't hold all the way up the ladder, but it's good to see Haley both keeping his walks and hits down, since last summer the lack of hits seemed, at least in part, to be due to his inability to find the strike zone.
He's a reliever in the making, though, the Sox will likely keep him starting for as long as possible if he can keep walks out of the equation. His grounder tendencies should make up for the loss of some swing-and-miss as he moves up through the system, but let's not get ahead of ourselves, since he has just 18 innings worth of High-A behind him.
Austin Maddox, RHP
Maddox's performance isn't flawless, but after last year's disaster I'll take this step up. He's been getting plenty of ground balls, with nearly twice as many as fly balls induced in his 15 innings, and while his strikeouts aren't where you want them to be, the lack of walks is a plus. Remember, too, that Maddox was a two-way player at Florida, and that he's not as advanced an arm as your average 23-year-old in High-A ball, especially not when he lost a significant chunk of his first full season to injury and awfulness.
He's worth keeping an eye on, as so many arms in the Red Sox system are, as he has a legitimate chance of becoming a big-league bullpen option. That might not sound like much, but building a bullpen is difficult: having a plethora of homegrown options to choose from can be a huge assist. Ask Drake Britton and Brandon Workman about that.