Follow the Prospects: Alejandro Rosario, RHP

[imref]

Alejandro Rosario, RHP
6'1", 182
DOB: 1/06/2002 in Miami, FL
Drafted in 2023, Texas Rangers, Round: 5, Overall Pick: 144
Acquired by the Nats on January 22, 2026 in the Mackenzie Gore trade

https://www.milb.com/player/alejandro-rosario-691730

MLB.com:

Scouting grades: Fastball: 60 | Slider: 55 | Splitter: 60 | Control: 60 | Overall: 45

Rosario rated as a top-three-rounds talent after reclassifying into the 2020 Draft as a Florida high schooler, yet went undrafted because he was strongly committed to Miami. He got pounded for a 6.47 ERA in three years with the Hurricanes before the Rangers took him in 2023's fifth round and gave his mechanics and pitch mix a makeover. The results were dramatic during his pro debut last year as he posted a 2.24 ERA between two Class A stops while ranking first in the Minors in K-BB percentage (33.1 percent) and second in strikeout percentage (36.9 percent) and K/BB ratio (9.9) among pitchers with at least as many as his 88 1/3 innings. But then he injured his elbow getting ready for Spring Training in February and required reconstructive elbow surgery that will sideline him until 2026.

Rosario operated at 94-98 mph and reached 100 with his fastball in 2024, and he found more success blasting it by hitters at the letters in pro ball than he did sinking it down in the zone in college. His 88-92 mph splitter was a swing-and-miss pitch with devastating tumble and run at its best last year. He has scrapped the curveball and cutter he toyed with at Miami to focus on an 83-85 mph slider that shows flashes of giving him a third plus offering.

After Rosario turned pro, the Rangers moved him to the third-base side of the rubber and had him keep his delivery closed longer to hide the ball better from hitters. He also creates some deception with his flat approach angle and his new mechanics have allowed him to pound the strike zone after he battled his control and command with the Hurricanes. Before he got hurt, he once again looked like the pitcher who intrigued scouts in high school and has the upside of a frontline starter.

BBA:

Two seasons ago, Rosario was one of the sport’s breakout pitchers. The Rangers bet they could unlock heaps of ability by tweaking the arsenal he employed during a middling career at Miami and were rewarded with a player who fricasseed the competition at Class A. Unfortunately, his career has been on pause ever since. A torn elbow ligament before spring training required Tommy John surgery, but the operation was delayed until 2026. As a result, he will miss all of the 2026 season as well. He’ll need to be added to the 40-man roster after the season, which could shelve him even further if the game goes into a lockout and rostered players are barred from playing in the minor leagues. His stuff makes him a solid gamble, but it will be a while before Washington can reap the rewards.

Keith Law:

Right-hander Alejandro Rosario was on my top 100 prospects list a year ago, but he injured his elbow in spring training and was supposed to undergo Tommy John surgery … but as far as I can tell, he still hasn’t had the operation 10 months on, and the Rangers have been extremely circumspect about his status. He is not expected to pitch in 2026 but is expected to return at some point after that. Before the injury, the Rangers had worked wonders with him, changing his approach to go mostly four-seamer up and splitters down (as opposed to his approach at the University of Miami, where he had a 7.11 ERA). He threw a lot of strikes and repeated his delivery well enough to see a long-term starter, until the mystery surrounding his health began.

[imref]

Per Golden, he will be undergoing TJ and will miss all of the 2026 season.

[Lintyfresh85]

He's the most exciting piece of the trade to me

[JCA-CrystalCity]

He's the most exciting piece of the trade to me

yes. I  don't suspect being added to the 40 man at the end of 2026 will cause a roster squeeze. If he comes back with anything like 60 command and a few of his pitches, this guy would be a core piece.

Can dream of a couple of guys among Rosario, Perales, Sykora,  Susana, Clemmey actually realizing their potential. That may be unlikely, but it's a cold weekend and need a diversion

[zimm_da_kid]

yes. I  don't suspect being added to the 40 man at the end of 2026 will cause a roster squeeze. If he comes back with anything like 60 command and a few of his pitches, this guy would be a core piece.

Can dream of a couple of guys among Rosario, Perales, Sykora,  Susana, Clemmey actually realizing their potential. That may be unlikely, but it's a cold weekend and need a diversion

My hope is one of them becomes a #2, one becomes a strong 4 or 5 and we get a setup guy or closer. That still allows for two total duds

[Slateman]

I just want to know what happened for the entire season. Remember how Cavalli just never made it back from TJS for a year? This feels like that. Actually, this seems way more concerning:

https://www.cbssports.com/fantasy/baseball/news/rangers-alejandro-rosario-still-hasnt-had-surgery/

"Grant adds that the Rangers and Rosario are working through some unrelated issues, so this situation is incredibly murky. The team announced in February that Rosario would need Tommy John surgery, but for whatever reason, he still hasn't had the procedure or advanced down a non-surgical path of recovery."

So what happened? He was so desperate to avoid surgery that he gave up a year? That seems ridiculous for TJS.

He's 6'1" and 182 lbs. This guy screams reliever risk.


Update: Toboni was on G&D and Grant asked him about the delay. Toboni said he had a small surgical procedure last year that delayed his TJS

[imref]

Odd. 

[imref]

Law says Rosario still hasn't had TJ.

[blue911]

Law says Rosario still hasn't had TJ.

Waiting to see if Medicare will cover a portion?

[imref]

Placed on the full-season IL. No idea yet if he ever had TJ.

[imref]

TalkNats says Rosario still hasn't had TJ and nobody knows what is going on with him.

[rbw5t]

If he refuses to have surgery, can we return him and settle on a different equivalent prospect who might actually be able/willing to play baseball?

[blue911]

If he refuses to have surgery, can we return him and settle on a different equivalent prospect who might actually be able/willing to play baseball?

No

[zimm_da_kid]

TalkNats says Rosario still hasn't had TJ and nobody knows what is going on with him.

freaking hilarious

[imref]

TalkNats says Rosario finally had TJ in March.

[Slateman]

So two weeks ago they claim he hadn't had it and yesterday they're saying he had it in March?

[imref]

So two weeks ago they claim he hadn't had it and yesterday they're saying he had it in March?

it just seems like there's a cloud of secrecy surrounding the guy. Maybe he's in whatever prospect witness protection program that House was in a few years ago?

[JCA-CrystalCity]

In general, they seem less forthcoming about minor league injuries. Still haven't seen why Mota was IL'd

[blue911]

In general, they seem less forthcoming about minor league injuries. Still haven't seen why Mota was IL'd

They don’t have to tell anybody anything. Teams don’t have to disclose the nature of injuries for minor leaguers.

[JCA-CrystalCity]

They don’t have to tell anybody anything. Teams don’t have to disclose the nature of injuries for minor leaguers.

For Mota, I googled up the blue rocks for game stories around the time of his last game played. I figured a game story might mention an injury, but couldn't find any coverage. IDK the Wilmington paper.

[JCA-CrystalCity]

Evaluating Rosario in light of his  injury:

12:42    
Eric A Longenhagen: Surgery was in March so see you next year. Looked like a top 30 overall prospect when last healthy. Obviously this is now a volatile situation beyond your usual TJ surgery, and arguably beyond the Forrest Whitley, Kumar Rocker group of oft-injured guys with maladies we’re at least familiar with. Gauging Rosario’s “value” is tough, this is just a gut feel where he belongs based on his upside.

https://blogs.fangraphs.com/eric-longenhagen-prospects-chat-4-24-26/

[nobleisthyname]

Ranked the 6th best team prospect by FanGraphs.

Fastball	|	Slider	|	Splitter	|	Command	|	Sits/Tops	|	FV
55/60	|	55/60	|	60/60	|	40/50	|	94-97/99	|	45+

A very famous prospect since his high school underclass days, Rosario’s mid-to-upper-90s fastball used to miss frustratingly few bats because of its shape. He ran an ERA over 7.00 during both his sophomore and junior year at the University of Miami despite sitting 95-96 mph with a plus slider and splitter. The Rangers quickly overhauled Rosario’s delivery, most notably his arm slot, which became much more vertical than when he was an amateur. It totally changed the way his fastball played without sacrificing his arm strength or the quality of either secondary pitch, and it also improved his command, as his line to the plate became much more direct and comfortable-looking than when he was in college. In a 2024 split evenly between Low- and High-A, he posted a 36.9% strikeout rate, a 3.7% (!) walk rate, and a 2.24 ERA across 88.1 innings.

Not long after the 2025 Top 100 list came out (Rosario was ranked 39th), the Rangers announced that he would need elbow surgery, though the exact timing of his injury was left vague. Months later it was reported that he still hadn’t had surgery, with Evan Grant of the Dallas Morning News saying the Rangers and Rosario were “working through some unrelated issues.” Industry sources indicated to me at the time that he had a separate, non-baseball medical concern that had to be resolved before his elbow could be addressed. He still hadn’t had surgery when he was traded to Washington in the MacKenzie Gore deal during the offseason, but a more recent report indicated he had surgery in March. Assuming a standard recovery from that point forward, he’ll be back in early-to-mid-2027 having missed two whole seasons.

The time off obviously creates a great degree of uncertainty about how Rosario will look when he returns, and the mysterious (and understandably private) nature of the issues that contributed to the delay in his TJ are even more difficult to account for when you’re trying to line him up on a prospect list. But his look and performance in 2024 — mid-90s heat and three plus pitches, including a potentially elite splitter — reads a lot like Trey Yesavage’s scouting report. This year would have been Rosario’s 40-man platform season, and he’s a name to file away for the next Rule 5 Draft if the Nationals choose not to roster him after the season.