It’s day three of our countdown of the top 25 prospects in the Cubs system.
11. Jostin Florentino. RHP. DOB: 12/01/2004. 6’0”, 175. International free agent (2023) Dominican Republic.
One of the disappointing aspects of the Cubs 2024 minor league season is that while players at the top of the system graduated to the majors (or were traded), the players near the bottom of the system did not, for the most part, rise to the occasion to take their place. You can’t say that about Jostin Florentino, who made one of the biggest leaps forward of anyone in the Cubs system and earned Cubs Minor League Pitcher Of the Year honors.
No pitcher anywhere in the minor leagues added more velocity on his fastball than Florentino did in 2025. Now the bad news is that means it went from averaging 84.9 miles per hour to 90, but if you think there’s another tick of velocity in there as he ages, then there could really be something there. On top of that, Florentino has a very simple and fast delivery with a low arm-slot release that doesn’t give hitters much time to react, allowing all his stuff to play up.
Florentino’s best secondary pitch is an upper-70s sweeper/slider that has a ton of spin and lateral movement. Florentino also has a cut fastball and a changeup that will have to improve to retire left-handed hitters as he moves up the system. But currently, left-handed hitters in the Carolina League are just as clueless against his stuff as right-handers are, so platoon splits aren’t a big issue yet.
Florentino made his US debut after spending two seasons in the Dominican Summer League. After 21.2 innings and a 3.74 ERA in Mesa, Florentino was promoted to Pelicans where he dominated the Carolina League. Over 11 appearances and ten starts for Myrtle Beach, Florentino went 4-3 with a 1.96 ERA. He missed a ton of bats in Low-A, striking out 10.1 batters per nine innings in Low-A and 11.2 per nine overall. His walk totals for a young pitcher in Low-A were also excellent as he walked just eight percent of the batters he faced.
Florentino’s results, albeit in just 81.1 innings between the two levels, indicate that he’s a potential major league starter. But the stat line runs into conflict with the scouting report. While Florentino has made big gains, he’s still just throwing 90-91 mph and is still mostly a two-pitch pitcher.
Florentino should start the season in High-A South Bend and all eyes should be on whether he can build on the gains he made in 2026. If he improves that velocity even more with no loss of control or develops a better third pitch, Florentino could be a top-five prospect in the system at this time next year.
Here are the highlights of a six-inning start for Florentino in June that featured nine strikeouts and no hits. [VIDEO}
12. Josiah Hartshorn. OF/1B. DOB: 2/02/2007. B:S, T:L. 6’2”, 200. Drafted 6th-round (2025), Orange Lutheran HS (CA).
I hate to rank high school players who have yet to make their professional debut, but in the case of Hartshorn, I’ve read and heard too much positive stuff to keep him out and at least there is some online video for showcase events where I can see his talents for myself. The Cubs also gave him $2 million to keep him from going to Texas A&M, which is bonus money commensurate with someone taken at the end of the first round. So this is probably a fair ranking of a guy with some sky-high potential.
The first thing you notice about Hartshorn is that he’s a huge man with a fairly level swing from both sides. He does have a bit of a leg kick that he apparently uses as a timing mechanism, but it’s nothing exaggerated. He also appears to be fairly athletic for someone as big as he is, which would be a positive for him staying at a corner outfield position. He does look like a natural first baseman, however, and that may be where he ends up by the time his career is over. He will have to maintain his conditioning to stick as a corner outfielder.
Hartshorn’s high school career was littered with injuries, which has led to some odd stuff. For his first three years in high school, a nagging left elbow injury meant that he batted almost exclusively from the right side. His elbow was better by his senior year, but then he suffered some back issues that made him bat mostly from the left side in his final year in high school. So while he is a switch hitter, he’s had plenty of experience facing same-side pitchers. Hartshorn’s left-handed swing looks more natural to me, but I’ve read scouting reports that like his right-handed swing better. He did tie for the championship in MLB’s High School Home Run Derby hitting exclusively left-handed. He had reportedly returned to hitting from both sides by the time of the draft last year.
In any case, Hartshorn has tremendous bat speed from both sides of the plate. He’ll probably need to get more loft in his swing to become a true power threat, but he certainly has a raw power ceiling of a 65 or 70 on the 20-to-80 scale. He’ll have to make good swing decisions for that to become game power, but the reports on that front are positive.
Because he’s so young, I’d expect Hartshorn to start this year playing in Mesa, but if the Cubs are really convinced he can handle it, Myrtle Beach isn’t out of the question. He certainly would hope to play for the Pelicans sometime this summer. Hartshorn is a guy with some real boom-or-bust potential. He could be a top-five prospect at this time next year with a strong 2026 season.
Here’s some workout video of Hartshorn at a showcase event before the draft.
13. Will Sanders. RHP. DOB: 3/30/2002. 6’6”, 230. Drafted 4th round (2023) South Carolina.
Sanders has been a tantalizing prospect since the Cubs drafted him in 2023. He has a lot of raw talent and has shown some real promise at times in the Cubs minor league system. However, he hasn’t shown the kinds of consistency that you want out of a major league starter.
Sanders is a big right-hander with a fastball in the 92-to-94 mile per hour range and it can touch as high as 96. His height gives hitters unusual release point to pick up the pitch from. He uses a mid-80s splitter as a changeup and both pitches can miss bats when they’re on. Sanders also features a curve and a slider, both of which are fringy. He does have above-average command, which allows his stuff to play up a bit.
Sanders started last year in Double-A Knoxville and it looked like he had put everything together. In the Southern League, Sanders made some major improvements in his control and he got good results over nine starts for the Smokies: 3-2 with a 2.64 ERA. The peripherals were even better as his walk percentage dropped from 10.3 percent in 2024 down to 4.6 percent. Meanwhile, his strikeout percentage stayed level at 25.1.
When you do that well in Double-A, you get promoted to Triple-A, so Sanders packed his bags and headed up to Iowa. Unfortunately, the gains he made in Double-A did not continue in the International League. Triple-A hitters lit up Sanders in Iowa and over 17 appearances (14 starts), he went 7-4 with a 6.38 ERA. Some of that was because of a poor strand rate, but a lot of that was because he gave up a ton of home runs. His walk rate also jumped up to 9.3 percent, which is still lower than it was in 2024 but not what he needs to succeed at this level and the majors.
Sanders should return to Iowa this summer and hopefully he figured out over the winter what he needed to work on. He is an emergency option for a major league debut this summer if he improves. Sanders has the upside of a number-five starter.
Here’s Sanders striking out nine over 3.2 innings for the I-Cubs in August. [VIDEO]
14. James Triantos. 2B/CF. B:R, T:R. DOB: 1/29/2003. 5’11”, 195 lbs. Drafted 2nd round (2021) Madison HS (VA)
James Triantos had a poor 2025 season. There’s no denying that. In his first full season at Triple-A Iowa, Triantos hit just .258/.315/.369 with seven home runs. He did struggle with leg soreness all season and missed most of June on the injured list because of it. That could be the reason for his downturn, which seems mostly related to an inability to pull the ball with authority at the same rates that he had in 2024. His swing decisions and contact rates remained mostly the same as the year before, although he only played 26 games for Iowa in 2024.
So was this past year simply a result of nagging injuries or have opposing teams found a weakness in his game? That’s the big question coming into this year.
Triantos, at his best, is a pesky hitter with terrific contact skills. He doesn’t get a lot of lift on the ball so his home run rates are always going to be low, but he does hit the ball hard. He’s also a terrific baserunner. He stole 31 bases in 110 games last year and 47 in 114 games the year before.
It’s been an adventure trying to find a defensive position for Triantos, The Cubs originally planned to make him a third baseman, but despite an above-average arm, he couldn’t handle the position. He was better after he moved to second base and the Cubs could live with his glove there as a bat-first second baseman. But the Cubs tried moving him to center field this past summer. The move made sense, as he has the foot speed and arm to play there. But so far, Triantos has struggled in center. Most of that can be chalked up to inexperience and it is entirely possible that he gets good out there with more repetition. He’s got the raw tools to succeed in center. On the other hand, you could have said that about his work at third base as well.
In any case, the Cubs still thought enough of Triantos to protect him from the Rule 5 draft this winter and place him on the 40-man roster. So he is still on track for his major league debut sometime this season. Right now he projects as a bench bat who is limited to second base and maybe the outfield. But he’s still young and if he can return to his earlier form, then there may be a starting second baseman or center fielder in there.
Here’s Triantos hitting a home run last September [VIDEO].
15. Ty Southisene. 2B. DOB: 7/08/2005. B:R, T:R. 5’9”, 170. Drafted 4th-round (2024) Basic HS (NV)
A lot was expected out of Southisene when he arrived in Myrtle Beach last May and for two months, he was terrible. His stat line for his first 33 games was .151/.318/.160. He was making contact at a decent clip, but it was weak contact and on the ground. But in the second half, Southisene improved his contact rates and started to barrel up the ball for harder contact. He looked like the guy the Cubs expected when they took him in the fourth round last year. Southisene hit .292/.422/.335 in the second half. That gave him an overall line of .244/.387/.276.
Southisene is from a baseball family—his younger brother Tate was taken in the first round last year by the Braves. His twin brother Tee played for Southern California last year but appears to have transferred to Southern Nevada, which would make him draft-eligible this year. He has another brother, Troy, who is committed to play baseball at Oregon State this upcoming fall, assuming someone doesn’t draft him and sign him away.
Southisene’s game is contact and speed. He has a good eye at the plate and even with his first-half struggles, only struck out in 15 percent of his plate appearances in his first year as a professional. He had 63 walks compared to 59 strikeouts. Southisene also boasts plus speed as he stole 41 bases in 49 attempts last year. His defense at second base is average, but his arm probably isn’t strong enough to play on the left side of the infield regularly.
The biggest concern with Southisene revolves around his small size, which limits his ability to hit for power. Of his 78 hits last year, 70 were singles, six were doubles and two were triples. He’s yet to connect for a home run as a professional and isn’t likely to hit many of them down the road. He might be able to gain enough muscle to hit a few every year, but his swing doesn’t really have any lift to it. Southisene’s ground ball rate last year was 59 percent and his fly ball rate was just 15 percent.
Without power, Southisene is probably limited to being a bench player in the majors. His arm also limits his utility as a backup infielder, but the Cubs have found ways to make below arms work on the left side of the infield before. But Southisene’s contact rates and base running skills still make him an interesting prospect.
Here’s a game in July where Southisene had three hits and two steals. [VIDEO]
Tomorrow: Prospects 6 through 10.