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 Seattle Mariners who will be on the Peoria Javelinas this fall. The team will consist of players from the Baltimore Orioles, San Diego Padres, Cincinnati Reds, and Minnesota Twins as well.

Julio Rodriguez playing for the Javelinas in 2019

Seattle Mariners:

Tyler Cleveland RHP: A really interesting pitcher, Cleveland is a submarine reliever who has been unhittable this season. Throughout 51.2 innings between High-A and AA he has a 0.87 ERA and 2.91 FIP. He struck out 25.5% of hitters this year but his strikeout numbers dropped from 31.6% in High-A to 16.5% in AA. His walk numbers also got worse in AA going from 7.7% in High-A to 10.1% in AA. Still he was able to limit any hard contact at both levels giving up no homers at both stops. He had 37 out of 41 games where he didn’t give up a run. Like most submarine pitchers he mostly throws his sinker that sits in the high 80s but gets a ton of weak contact. He also throws a sweeper that sits around 74 mph and gets more than 15 inches of horizontal break; he uses it as his big strikeout pitch. At times he will throw a changeup and harder slider to keep hitters guessing. He has a chance to make the Mariners after next spring especially with the advanced age of 26 he’ll likely start in AAA at worst. 

Christian Little RHP: After being drafted in the 11th round in last year’s draft Little is already getting comparisons to current Mariners starter Bryan Woo. They both came out of college with pretty awful numbers but good enough stuff the Mariners felt they could mold them into great starters and within the first year for Little it’s happening. In college after 2 years at Vanderbilt he transferred to LSU and mostly came out of the bullpen in his senior year at LSU in 2024 he had a 6.37 ERA but there were signs that something was there with his 3.23 FIP. In his first professional season this year he pitched 61.2 innings in Low-A even after being put on the injured list for bone spurs that kept him out for all of July. Little was then promoted and pitched two starts in High-A for 9 innings total. He had a 3.95 ERA between both levels with a 24.9% strikeout rate and his lowest walk rate since his sophomore year at Vandy with a 10.9%. Little has a full pitch mix already with a fastball that sits in the mid 90s but tops out at 99 mph. He pairs that with a curveball in the upper 70s with a ton of drop. He’s also been developing an upper 80s cutter that's been getting good results. He will probably be ranked within the Mariners prospect rankings next season. 

Brock Moore RHP: Standing at 6’6” the former Oregon pitcher and 7th round pick had a disappointing first year in pro ball. In High-A he struggled to throw anything for strikes with a 26.7% walk rate leading to his ERA to jump to 9.64. He was able to get strikeouts as his stuff should he struck out 24.8% this year but the command issues are scary. I talked about Moore after an outing this spring where his stuff looked phenomenal against the Dodgers spring team but he had absolutely no idea where it was going. Moore has a slider that he throws in the high 80s with great movement and is his main pitch to get ahead as he has the most feel for it. His fastball which tops out at 100 mph and sits around 97 mph is nasty with 16 inches of induced vertical break. He also has a high 70s curveball with 17 inches of horizontal movement. He has 3 big league pitches right now that would work in the Mariners bullpen today but he’ll never make it out of the low minors with that command. I will say Moore was figuring it out with four outings of no runs in June before being injured for all of July. He still has two years before needing to be on a 40 man roster so he has plenty of time to figure it out and with the Mariners pitching lab I’m sure they have something cooking this fall. 

Marcelo Perez RHP: After dealing with injuries during the start of the season and end of the season Perez ended up putting a good season together. He made 8 starts for 35.1 innings in High-A where he really struggled the year before but dominated this season. This season in High-A Perez had a 2.04 ERA striking out 25.4% of batters and showing off his elite command only walking 3.7% of batters. He then rightfully was promoted to AA and struggled striking out only 11.9% and upping his walk rate to 7.6%. This led to his ERA jumping to 4.31 in 56.1 innings. Unlike another Mariner starter with great command George Kirby, Perez doesn’t have the high level stuff to be able to compete at the higher levels. His fastball only sits in the low 90s and can get hit hard at times. His main pitches are two sliders, one a more gyro like slider that sits around 87 mph and a low 80s sweeper that had great late movement. Those pitches and his control could carry him into a low leverage reliever at the MLB level but he’ll need to either have an uptick in his velocity or add another pitch like a changeup or curveball to have the potential to break into a MLB rotation.

Stefan Raeth RHP: The former 17th round pick in 2022 dominated High-A this season with a 2.06 ERA. In 39.1 innings in High-A Raeth struck out 29.7% of batters the most of his career and only walked 4.7% the least of his career. He obviously earned a promotion to AA and struggled a bit, his ERA went to 5.50 in 18 innings but he still struck out 23.1% of batters and kept his walk rate down to 7.7%. He’s a reliever that can go multiple innings at his best and even had three starts at the end of his season. He has a big league pitch mix but his primary pitches aren’t the best stuff wise. He throws three fastballs: a four seam, cutter, and sinker that all sit in the low 90s or high 80s (cutter). He’s able to command these really well though and when they’re working can get weak contact. His breaking pitches are really good and are mainly used as strikeout pitches. His curveball sits in the high 70s and gets great late drops while his slider is nasty with over 15 inches of horizontal break. He’s shown at the very least he can be a solid reliever depth option but with this offseason being his rule 5 decision time the Mariners need to see more this fall.

Brock Rodden 2B: All Rodden has done his whole minor league career is hit and this season was no different. Even after battling an oblique injury that kept him out for basically two months Rodden still put together a good 37 games in AA with a .295/.356/.466 slash line with a 139 wRC+ until his season was ended by a broken hamate bone. Rodden seems to be recovering well because he’ll come into the Fall League ready to hit. He spent the early part of his minor league career as a contact oriented hitter but had a breakout power season in 2024 with a .416 slugging percentage and 14 homers and showed this season that wasn’t a fluke hitting 5 homers in 37 games and is said to have his highest exit velocities ever. He adds that to his ability to steal bases and play solid defense all around the infield. His strikeout rate though is concerning, going from 22.7% last season to 30.1% in his shortened year this year. His walk rate also dropped 3% to 7.4% this year. He’s making less contact which for a 5’7” infielder is very concerning since his power likely won’t translate as he gets to higher levels. It’ll be interesting to see how he performs this fall after the injury.

Jonny Farmelo CF: The highest ranked prospect on the Mariners fall league roster. Farmelo was the 29th pick in the 2023 draft out of high school but has struggled with injuries in his first two pro ball seasons. In 2024 he looked good in Low-A slashing .264/.398/.421 for a 126 wRC+ in 46 games before tearing his ACL while making a catch in the outfield. In 2025 He was ready to go at the end of April and hit really well before suffering a stress fracture in his ribs during a swing and missing all of June and July. Since coming back in August he’s not looked good with a .191 average during the last 18 games of the season. He’s shown big raw power and that mixed with his elite speed makes him a high potential outfielder especially in center field but his contact concerns especially this season need to be fixed. He struck out 29.5% of the time in High-A a jump from the season before and walked 6% less. He also only made contact on 64.5% of swings and whiffed 36.7% of the time. Farmelo’s only in his 20 year old season and hasn’t been able to have a full non injured season. I still have high potential for him to figure it out especially after a hopefully fully healthy offseason.

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