The Baltimore Orioles promoted outfielder Dariel Alvarez to the major league roster yesterday. Originally signed out of Cuba in 2013, he's spent the last two years primarily at the Triple-A level, looking for a job on the major league bench. His 2014 season was quite good (.306/.330/.472 in the high minors) but his 2015 (.275/.325/.424) was less impressive. He hit .241/.290/.379 in a 12-game trial with the Orioles last summer.
From the 2016 Baseball Prospect Book:
Dariel Alvarez, OF, Baltimore Orioles
Bats: R Throws: R HT: 6-2 WT: 180 DOB: November 7, 1988
2014: Grade C; 2015: Grade B-
I gave Cuban outfielder Dariel Alvarez an optimistic Grade B- last year but that looks like a mistake. He’s not without positive attributes: he has some power, is adept at making contact, and is a competent defensive outfielder. However, he is a very impatient hitter and his OBP is almost entirely dependent on his batting average, which is a big problem when you look like a .260 hitter as Alvarez does. He’ll either need to significantly boost his isolated power or his on-base abilities to play regularly, and unfortunately at age 27 that’s not terribly likely. He still has a chance as a role player and bench asset. Grade C.
Alvarez has remained just so-so this year in Triple-A, hitting .271/.309/.363, and the pre-season assessment hasn't changed. On the right day he'll show some nice doubles power but his on-base abilities are spotty and without more home run power (or a seemingly unlikely surge in batting average), there doesn't look like there's enough offense here for him to start regularly for a good team.
He does beat up lefties fairly well (.295/.333/.459 last year, .300/.320/.414 this season) and is a good defender at either corner so he does have the potential to be a useful role player. At his age, huge, sustained improvement seems unlikely. On the other hand, he is right at the age 27/28 window where some players have an offensive surge. It's not happening yet, but I suppose it is possible he could out-perform expectations at some point.