Red Sox prospects daily: Yoan Moncada just keeps getting better

High-A Salem: Yoan Moncada, 2B

Moncada hit .316/.450/.418 in April. He then batted .277/.402/.489 in May, more than doubling his extra-base hit output from the month before in just five more games and 18 additional plate appearances. June is off to a wonderful start as well, with Moncada at .304/.385/.609 with seven doubles through the month's first six games. He just keeps getting better and better, and it seems like he'll be in Double-A before too long.

There are some issues to watch out for, of course. The first is the defense, as Moncada still isn't excelling at second, where he has 10 errors in 51 games. Errors are not a great way of measuring defensive prowess, of course, but even the usually optimistic Red Sox scouting contingent hasn't had much to say about his glove yet. Moncada is also performing much worse against lefties than righties -- .224/.356/.285 with three doubles in 59 plate appearances. While it's a small sample, southpaws aren't going to get any easier as he climbs the ladder.

He'll catch up eventually, though, and we are talking about a pretty small sample. It's just easy to notice when Moncada isn't doing spectacularly, because much of his game is wonderful.

Triple-A Pawtucket: Roenis Elias, LHP

Elias is possibly the top candidate to be Boston's fifth starter beginning June 18, in part because everyone else in line fell behind with their own big-league performances this year. He's off to a convincing start since Sox manager John Farrell made it an open competition, as the lefty went the distance in Sunday's start, striking out eight batters against one walk with a solo homer the only damage.

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His season looks a little off even with this performance, especially for someone with nearly 300 major-league innings behind him. Most of that came from a single start where he couldn't stop handing out walks, though: Elias gave out seven free passes in five innings in one start a month ago. He actually pitched around those walks for the most part, giving up just three runs and six hits, but if you cut that one day out of his season, his walk rate is a much more Elias-like 3.7 per nine. His ERA would also be 3.85, his strikeout rate an even one per inning with a strikeout-to-walk ratio of 2.5... his whole season would look different.

That's not perfect, no, not even after our little adjustments, but the Sox aren't looking for Elias to shore up the top of their rotation. They need a fifth starter who won't actively harm them -- as Joe Kelly and Henry Owens have and would -- and Elias is the man for that job. Another strong outing in his next turn in the rotation, and that June 18 start will be his for the taking.

Double-A Portland: Justin Haley, RHP

When a rotation spot inevitably opens up in Pawtucket, it needs to go to Justin Haley. Elias will likely be in Boston later this month, as explained above, but even then, the PawSox are going to have five starters: Joe Kelly, Henry Owens, William Cuevas, Sean O'Sullivan, and the recently promoted Aaron Wilkerson. Cuevas seems the easiest to bump -- you don't want the Sox to have to break the glass in the emergency case they store O'Sullivan in, but better safe than sorry and all that, so he should stay stretched out. When the Sox make a decision one way or another, Haley should be the beneficiary.

He's striking out 8.7 batters per nine, has a 2.49 ERA, has his control as, well, under control as he probably can, and has made it to the sixth inning -- and as late as the seventh -- in five of his 10 starts. It's time for a new challenge for the right-hander, whether the long-term plan is relief or starting. Haley still has potential to start at this moment, though, so for now, the Sox need to figure out how to make room in Rhode Island for him just in case he can reach that goal.

Low-A Greenville: Anderson Espinoza, RHP

Espinoza is just 18 years old and in his first full-season league, and it's shown at times. He has one start where he allowed six runs, and four of his 11 have been for between just 1-2/3 and four innings. On the whole, though, there's a lot to love here. Espinoza has struck out over a batter per inning and has a 2.6 K/BB. When his stuff comes together, he's been great, as he's allowed one or zero runs in six of his 11 starts, and just two in another.

The Sox aren't going to open up his pitch count this summer -- Espinoza is averaging 71 pitches per outing and has topped out at 79 -- but that's what his age-19 season will be for. And since the Sox have Espinoza in the low minors at 18, and presumably at least to begin his age-19 campaign next year, he looks like he'll be on track workload-wise by the time he gets to the majors a few years down the road. Or, at least, close enough where if they need him for more than a few starts, he'll be in a position to help. That's jumping just a teeny bit ahead, though. For now, let's just be happy Espinoza is showing plenty of flashes against much older competition.