Outfielder Yusniel Diaz’s biggest claim to fame so far, arguably, is being known as the guy the Orioles got in the Manny Machado trade; or at least the main guy, considering that it was a 5-for-1 swap.
The right-handed hitting outfield prospect was the most hyped of the bunch coming over from the Dodgers and looked to be the player with the highest ceiling. Shortly before the July 2018 trade went down, Diaz was ranked 31st on Baseball Prospectus’ 2018 Prospects: The Midseason Top 50 list.
A native of Cuba, Diaz’s baseball career began at age 17 with the Industriales of the Cuban National Series. He played in 65 games from 2014-2015, hitting .348/.447/.440 with 12 doubles, three triples, 19 RBI and seven stolen bases in 15 attempts. His OPS was .887, although he did not hit any home runs. He did earn more walks than strikeouts over than time span, 36 to 33.
His home run power started to appear in 2016 once he was in the Dodgers system, when he hit nine home runs, eight doubles and seven triples over the course of 362 plate appearances between Rookie level and high Single-A. His cumulative triple slash line that year — at age 19 — was .267/.326/.415.
In 2017, Diaz split his season between high Single-A and Double-A. At the former level, he had a .278 batting average and .757 OPS with eight home runs, 15 doubles, three triples and seven steals. In about a third the number of games at the latter level, he had a .333 average and .881 OPS with eight doubles, three home runs and two steals.
The young outfielder set a new career high in OPS (.905) in 2018 while playing 59 games at Double-A in the Dodgers system. He also had 10 doubles, three triples, six home runs and eight steals in 220 at-bats. Then the Machado trade happened.
Relocated from the Texas League to the Eastern League, Diaz appeared in 38 games with the Bowie Baysox and put up uninspiring numbers in the second half of the 2018 season. He slashed .239/.329/.403 at the plate . His .732 OPS was the lowest for any stretch of his professional career, including his time playing for the Industriales in Cuba.
Yet still, in November 2018 Baseball Prospectus ranked Diaz as the Orioles’ number one prospect. On MLB Pipeline’s list of top 30 prospects in the Orioles’ organization, Diaz is currently ranked 5th best.
Injuries were problematic for the young outfielder this past season as well though. He spent two stints on the injured list, from April 26 to May 29 and then again from August 2 to August 22. Aside from nine rehab games with Frederick and Aberdeen combined, Diaz spent the rest of his time at Double-A Bowie (76 games). In 322 plate appearances with the Baysox, he hit .262/.335/.472 with 11 home runs, 19 doubles, four triples and an .807 OPS. He was caught stealing three times in three attempts.
While Diaz has shown the ability to steal roughly a handful of bags every year, he also gets caught stealing frequently too. Across parts of four minor league seasons, Diaz has stolen 28 bases and been caught stealing 38 times. That comes out to a 42% success rate, if my math is correct. So it’s fair to wonder how that particular part of his game will translate to the major leagues where pickoff moves and catcher’s arms are the best in the world.
On Diaz’s Fangraphs page, his projected ETA is still listed as 2019 even though that time has come and passed. In spring training it looked like Diaz was destined for the big league club this year, as he impressed with a .306/.316/.472 slash line in 36 at-bats. But we know how cautious this front office is with promoting young players. Plus the injuries have not done any favors for Diaz’s upward mobility.
Looking at Diaz’s age (23 years old) and how the O’s handled similar prospects this year, there’s a chance he may not even get to Baltimore in 2020. Look at Ryan Mountcastle, who is only one year younger than Diaz and did not even get a look in September after his monster 2019 season with the Tides because Mike Elias did not want to rush him.
Diaz has not registered a single Triple-A at-bat yet in his career. There’s a chance that Orioles fans could see him in Baltimore mid-to-late 2020, but it could be even later than that, like 2021. With this rebuild, that would not be much of a surprise.