A Full Breakdown of the Seattle Mariners prospects headed to the Arizona Fall League

The Arizona Fall League rosters have been released this week with a lot of intriguing prospects on each team. There are six teams full of prospects from Major League teams that will play starting October 6th. I’ll be writing an article and making Twitter posts about each team’s roster. This will cover the prospects from the Baltimore Orioles who will be on the Peoria Javelinas this fall. The team will consist of players from the Seattle Mariners, San Diego Padres, Cincinnati Reds, and Minnesota Twins as well.

Baltimore Orioles:

Luis De Leon LHP: After a great end to 2023 and start of 2024 in Low-A De Leon was promoted to High-A in 2024 and really struggled with control and was getting hit really hard. After starting the 2025 season on the injured list with an elbow injury he made 4 rehab starts in Low-A and looked about the same as he did in High-A the year before walking 16.3% of batters and having a 4.09 ERA but he then was sent from his rehab to High-A and looked really solid dropping his walk rate to 10.1% in 60.1 innings while striking out 26.7%. He was throwing more strikes in the zone and getting weaker contact than the year before. This earned him a promotion at the end of the year to AA where he made 3 starts for 16 innings and looked phenomenal. He kept his walk rate around 10% and struck out 35.3% of batters. This earned him a 1.69 ERA and 1.60 FIP in those 3 starts. De Leon has a sinker that sits 96 mph and can top out in the high 90s. If he can command the sinker especially near the top of the zone it really works. He also throws a slider that sits in the mid 80s that has a really good sharp break and gets a lot of chases. His third pitch is a changeup that he commands really well arm side and has averaged around 20 inches of horizontal break. He has the potential to be a really good mid rotation starter if he can continue to command his sinker well but the floor is still a great lefty out of the bullpen. De Leon is definitely a prospect to keep an eye on this fall. 

Carson Dorsey LHP: After being drafted out of Florida State in the 2024 draft Dorsey was only able to pitch 0.1 of an inning after being drafted where he gave up 4 runs before being pulled and shut down until this season. Dorsey’s season didn’t start until late June because of an undisclosed injury and after one alright rehab start in the Complex League he made his Low-A debut and ended up pitching in 42.1 innings. He looked pretty good there with a 4.04 ERA and 2.41 FIP. He was able to strike out 33.1% of hitters and walk 9.7%. His ERA was inflated by two starts where he gave up 6 runs but he had some really impressive starts especially his last two where he pitched 10.2 innings total giving up 6 hits 1 earned run while striking out 13 and only walking 2. He has a really deceptive delivery that allows his stuff to play up. He has a low to mid 90s fastball that he commands really well. Plus a slider, changeup, and curveball that all get solid chase and are actually thrown for strikes more than half the time. I can easily see Dorsey getting on top prospect lists before next season especially if he has a solid fall league.

Andy Fabian LHP: Not much is known about the 2023 international signing out of the DR but Fabian has looked fantastic this year in his first state side action. Starting in the complex league he pitched 17 innings to a 2.12 ERA. He struck out 34.7% of batters but showed his bad command walking 16%. He then was promoted to Low-A Delmarva and he got even better pitching in 22.2 innings for a 1.19 ERA. Somehow he struck out even more hitters at 38.7% but walked the same amount. Fabian also gets an incredible amount of ground balls going back to his outings in the Dominican Summer League last season. In Low-A he had a 65.8% ground ball rate. He throws a fastball that touches 97 mph which is great for a 22 year old lefty. He also throws a slider that is nasty especially against left handed hitters. His last pitch is a changeup that he has the most control over and is a great third pitch. If Fabian can clean up the command with the fastball and slider he’s an amazing left handed relief prospect and I’m super excited to get some Statcast data on him this fall. 

Zach Fruit RHP: After an impressive spring Fruit started the season in AA and struggled in three starts and was put on the injured list with a right lat strain. He was out until July where he made two rehab starts in High-A before moving back up to AA where he again struggled especially with command. In 43.2 innings this season in AA he walked 14.2% of batters. His strikeout rate also dropped to only 19% this led to his ERA being 7.01. He has impressive stuff though with a fastball that sits in the high 90s and can top out at 100 mph. He also throws a slider with great movement and a low 90s cutter that gets weak contact. The stuff can carry him to be at least a solid reliever in the big leagues. He’ll need to focus on command to be able to stick in the rotation and likely add another pitch to get left handed hitters out. 

Tanner Smith RHP: Acquired at the deadline from the Padres in the Ryan O’Hearn and Ramon Laureano trade, Smith is in his first pro ball season after being drafted in the 15th round of last year’s draft and has already moved from the Complex League to High-A. He’s already shown great stuff with a 3.38 total ERA across all levels and teams this season with a 2.73 FIP. He has strikeout stuff with a 30.8% strikeout rate this season and kept his walk rate which was a major problem at Harvard to 10.7%. He’s listed by Baseball America as a player to watch this season for a reason standing at 6’6” and 245 pounds he has great stuff with a fastball and sinker that sit in the upper 90s. He also has a changeup in the high 80s and slider that sits in the mid 80s for an already high level pitch mix. He’s likely a pitcher who comes out of the bullpen but will be really exciting like all these Baltimore pitchers this fall.

Ethan Anderson C: Drafted in the 2nd round of the 2024 draft Anderson has already moved to AA in his first professional season. He’s a very contact oriented bat slashing .257/.338/.355 for a 109 wRC+ in High-A this season before the promotion. In his last 20 games in High-A he had a 183 wRC+ while walking 5 more times than he struckout. That hot streak ended in AA where he was still making good contact but those balls didn’t find outfield grass enough and he slashed .215/.338/.277 for a 80 wRC+. He was able to walk more than he did in High-A though and showed his elite contact skills barely swinging and misses or chasing. Defensively Anderson isn’t the best behind the plate; his arm coming out of college is what made him drop to the late 2nd round and the Orioles have already experimented with him at first base and at both corner outfield positions. Unlike other teams the Javelinas this fall have 3 catchers on the roster with top 100 prospects Ethan Salas and Alfredo Duno making the team so it seems Anderson will get playing time elsewhere as he develops this fall. 

Enrique Bradfield Jr. CF: A very interesting prospect, the Orioles took Bradfield with the 17th overall pick in 2023 out of Vanderbilt. At the plate Bradfield isn’t going to show off a lot of power with just a .106 ISO this season but he makes elite swing decisions rarely chasing breaking balls out of the zone and he makes elite contact especially in the zone with a 90% in zone contact rate the past two seasons. He rarely hits the ball hard only maxing out around 104 mph exit velocities but he slaps the ball around the field. He also has elite speed, maybe being the fastest player in the minors allowing him to beat out a bunch of infield hits and bunts. That speed also allows him to cover a bunch of ground in center even though his arm is only about average he makes up for it by stealing extra base hits away with his speed. He dealt with a hamstring injury in April and after a few rehab games he eventually was back in the AA lineup a little over a month later until he again suffered a hamstring injury and missed most of July. This led to him not using his speed on the bases, only stealing 36 bags in 76 total games unlike last season where he stole 74. In total he was able to play only 50 games in AA throughout the season but hit well with a .269/.393/.386 for a 124 wRC+ this led to him getting promoted to AAA for the last month of the season where he really struggled. His contact rating was still high but he ended up chasing 30.9% of pitches out of the zone and struck out at a 30.6% rate almost double what he was doing in AA. Hopefully he can go back to what was working this fall. 

Thomas Sosa OF: The exact opposite of his new teammate Bradfield. Sosa is a big framed lefty with pretty bad contact ability but big time power. In 2024 his first season in the states he struggled with contact going from the Complex League to Low-A and ending with 19 games in High-A where he really struggled only hitting .181/.298/.194. He showed his raw power with some of the highest exit velocities in the entire Orioles system but was only able to hit 4 homers in the Complex and 4 in Low-A. This season he again was in High-A but after only 4 games he hit the injured list with an undisclosed injury and didn’t return to High-A until July. He ended up playing 47 total games in High-A and actually hit pretty well with a .222/.309/.407 slash line and a 112 wRC+. He was walking at a 9.4% rate and cut his strikeouts down from 33.3% in High-A in 2024 to 24.1% this year. He rightfully earned a promotion to AA being one of the youngest players in the league at 20 years old but really struggled in only 11 games there hitting .158/.220/.342 for a 54 wRC+. He was walking less and making very weak contact but still showed off his power with 2 big homers in his first four games. It’ll be interesting to see if Sosa can fix some of his contact skills and bring his raw power into more games. If he can, he'll shoot up prospect lists.

Thank you for reading for shorter breakdowns check out my Twitter @drew-durstock. Each day I'll release a new team's prospect breakdown.