Joelvis Del Rosario is Starting to Make a Name For Himself

The Pittsburgh Pirates were busy with international free agent signings during the 2017-18 signing period, especially in the early stages of 2018 when most teams had already finished their signings. One of the under-the-radar signings in January of 2018 was a 16-year-old right-handed pitcher from the Dominican named Joelvis Del Rosario.

Del Rosario didn’t get much of a chance during the 2018 season in the Dominican Summer League. He had strong results, but he was limited to seven relief appearances. He then repeated the league as a starter in 2019 and put up a 3.40 ERA, 1.25 WHIP and a 43:16 SO/BB ratio in 50.1 innings.

After the 2020 minor league season was canceled, Del Rosario pitched in the Florida Complex League last year, where was being used as a starter and reliever. He had a 3.26 ERA, a 1.09 WHIP, a .224 BAA and a very impressive 52:10 SO/BB ratio in 38.2 innings.

It’s been a slow path to full-season ball for Del Rosario, who doesn’t have a big frame for a pitcher, standing in at 5’11”, 170 pounds. He has pretty much flown under the radar until this season. So it was a bit of a surprise to see him in the Bradenton rotation this year, figuring some more prominent names would get those spots. He has been pitching well, posting a 3.34 ERA in 29.2 innings, with a 29:8 SO/BB ratio. He has been even better in May, with a 1.35 ERA and a 1.00 WHIP in 20 innings.

The numbers aren’t the most impressive thing about the 21-year-old Del Rosario. He actually has some great stuff to go along with those numbers.

Del Rosario has a four-pitch mix, led by a four-seam fastball that sits 94-96 MPH early in outings, which you’ll see drop down a tick later in the contest. He also throws a sinker, which is in the 90-92 MPH range. As you can imagine from those low walk rates, he controls his fastball/sinker well. From what we have seen, the four-seamer gets a majority of the usage (ballpark guess that it’s about a 75/25 split). We have Statcast numbers, but they mix the two pitches, so those numbers work better for his other two offerings.

Del Rosario throws a changeup in the 86-88 MPH range, which he used often against left-handed hitters. That pitch also loses a tick later in games, going more 84-86 MPH. According to Statcast, his average changeup is 86 MPH, which is right in the middle of what I saw from him.

His final pitch is a slider and I did not see the pitch too often in his start that I watched before writing this article. However, he uses the pitch about 19% of the time according to Statcast numbers. Pitchers at the lower levels could always be working on a certain pitch one day, which will make certain games look like outliers, so that could explain the slider usage on a given day. The pitch was in the 79-82 MPH range and he finished off his five inning outing that day with a strikeout on the slider.

Here’s a video with some clips from that start, put together by Anthony Murphy from the Bradenton broadcast.

Del Rosario gets a little lost in the Bradenton rotation. He doesn’t have the high bonus tag like Anthony Solometo and Po-Yu Chen. His stuff isn’t as electric as Carlos Jimenez. He doesn’t have the strikeouts of Luis Peralta. Even Justin Meis has the local Pittsburgh connection that draws attention to him. Manager Jonathan Johnston believes his upside is just as high as everyone else.

“I’ve seen a great work ethic,” Johnston said of Del Rosario. “I’ve seen the right type of intensity, the right type of focus, and a high standard for himself. He’s worked really hard, and he’s been very consistent for us. One of our top performing guys. I don’t know where he thinks his limit is. He doesn’t have a limit. He’s just trying to get as good as he can, and I see that in his workdays. He’s got the right frame of mind. It’s great to see a young guy like that, first time in this league, attack it like that. It’s rare to see that immediately, and he’s been doing that.”

Del Rosario looks to be making a name for himself, especially with his recent performance. He’s got the mid-90s fastball that you like to see. He’s got a four-pitch mix and excellent control. His slider has a 50% whiff rate. He’s getting the results to match the stuff. He’s worth keeping an eye on this season in Bradenton.


Williams: The Growing Pains of Single-A

Carlos Jimenez Has Emerged As One of the Pirates’ Best Lower Level Pitching Prospects

Anthony Solometo: High Changeup Usage Highlights Debut

Bradenton Statcast: Who Is Hitting The Ball Well?

Tsung-Che Cheng: “He’s the type of guy who has an elite level of focus, an elite level of drive”

Joelvis Del Rosario is Starting to Make a Name For Himself

Brenden Dixon: Approach Leading To Success As Bradenton’s Table Setter

John started working at Pirates Prospects in 2009, but his connection to the Pittsburgh Pirates started exactly 100 years earlier when Dots Miller debuted for the 1909 World Series champions. John was born in Kearny, NJ, two blocks from the house where Dots Miller grew up. From that hometown hero connection came a love of Pirates history, as well as the sport of baseball.

When he didn't make it as a lefty pitcher with an 80+ MPH fastball and a slider that needed work, John turned to covering the game, eventually focusing in on the prospects side, where his interest was pushed by the big league team being below .500 for so long. John has covered the minors in some form since the 2002 season, and leads the draft and international coverage on Pirates Prospects. He writes daily on Pittsburgh Baseball History, when he's not covering the entire system daily throughout the entire year on Pirates Prospects.

Support Pirates Prospects

Related articles

join the discussion

Notify of
Oldest Most Voted
Inline Feedbacks
View all comments

Good article…I didn’t know a lot about this kid beforehand. Great numbers so far this year in Bradenton despite being on a team devoid of offense. If he keeps this up, he needs moved to High A soon. Size is the obvious concern, but pitchers like Keller show that having prototypical size isn’t a ticket for success.


I love the speed separation on his three pitches.


Definitely a name I wouldnt have known about other than this article. Love to have another guy to have hope for!


Another reason to love this site. I like the tweeners/complementary pieces that are just ball players that maximize their abilities. He seems like a sleeper to keep an eye on; they don’t all have to be 6’4″ and 225.


He’s impressive to see. When I went down to Pirate City for ST, everything had changed and only one or two fields were open to the public. Lucky for me, they were playing an A Ball game against the affiliate from the Orioles on one of the fields and Del Rosario was the SP for the Pirates. Very smooth delivery and a lot of gas to start the game. He mixed his pitches well and stayed in zone.

One of those kids who will help the Pirates in some capacity as he matures.

Share article

Pirates Prospects Daily

Latest articles

Pirates Prospects Weekly

MONDAY: First Pitch

TUESDAY: Article Drop


THURSDAY: Roundtable

FRIDAY: Discussion

SATURDAY: Pirates Winter Report

SUNDAY: Pirates Business

Latest comments

Would love your thoughts, please comment.x