The Chicago Cubs announce their Arizona Fall League roster: An Overview

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 Chicago Cubs who are on the Mesa Solar Sox this fall. The team will consist of players from the Athletics, Miami Marlins, Tampa Bays Rays, and New York Yankees as well.

Chicago Cubs:

Thomas Mangus RHP: A very underrated prospect the Cubs stole from his commitment to Oklahoma in the 18th round last season Mangus started this year on the injured list with an undisclosed injury. He has since pitched 3.1 innings in the Complex League and was promoted in July to Low-A. He has been kept off the field for the most part for Myrtle Beach, only pitching in six games for eleven innings since joining the team. In those innings he’s been good with a 0.82 ERA but he’s been unable to get whiffs in Low-A and is only striking out 14% of batters while walking 18.6%, that’s made his FIP 4.14. Coming out of the draft he was said to have a fastball that sat in the mid 90s and could get to 97 mph with arm side run. His biggest pitch was a slider that sat in the mid 80s and got a ton of swing and misses from right handed hitters. He also had a change up and curveball that he would mostly throw to left handed hitters. There was a chance he’d join the organization as a starter but as he works his way back from injury he’s only topped out at 44 pitches in a three inning outing. I’m very intrigued to get his Statcast outings this fall and see how he’s been developing. 

Luis Martinez-Gomez RHP: An intriguing arm in the Cubs system, Martinez-Gomez missed most of his first pro-ball season on the injured list in 2024 only making ten appearances in 33.2 innings between the Complex League and Low-A. This year starting in Low-A Martinez-Gomez had an interesting season. He had a 1.89 ERA and a 31.1% strikeout rate but his FIP was up to 3.62 because he walked 18% of batters. He still was able to earn a promotion to High-A South Bend and in his first ten appearances and 17.1 innings something has clicked as his walk rate has dropped down to 5.8%. His strikeout rate also dropped but still to a solid 23.2% and he’s still limiting runs with a 0.52 ERA and 2.43 FIP. He’s got some really solid stuff with a fastball that tops out in the mid 90s, a slider that works against right handed hitters, and a splitter that gets a good amount of chases. He’ll be really fun to watch this fall and I’m super excited to see his Statcast data.

Koen Moreno RHP: Since being drafted out of high school at the end of the 2020 Moreno has dealt with a ton of injuries. He didn’t pitch a single inning in pro-ball in 2021. Then in 2022 he was only able to throw twenty eight innings before being injured again. In 2023 he was never placed on the injured list and was technically on the Low-A roster the entire season but only pitched a few games a month and totalled 71.1 innings. He looked okay in those games with a 2.90 ERA but his 18.3% walk rate hurt him a lot. In 2024 he only was able to throw 23.1 innings until he was injured in early June and was out for the season. This season he recently came off the injured list on August 16th and has thrown twelve innings in four appearances to a 2.25 ERA. The walk problems are still there with a 16% walk rate but his stuff is obviously still alive with a 30% strikeout rate this season. It’ll be fun to get some innings from him this fall to build off of for next season.

Mathew Peters RHP: After being suspended last season for testing positive for a banned substance the former 12th round pick in 2022 has spent the season between the Complex League and Low-A. Even though he has an advanced age for each of those leagues Peters has struggled at both levels with a 6.46 ERA in the Complex League and a 8.31 ERA in Low-A. He has mainly struggled with walks walking an average of a batter an inning throughout thirty seven innings out of the bullpen this season. With this offseason being Peters' decision point for the Rule 5 Draft I’m guessing the Cubs want to see as much as they can before making that decision.

JP Wheat RHP: The big armed prospect was getting very good reports this spring but has been injured since June. In his seven appearances in Low-A though he had a solid 4.09 ERA and 4.45 FIP. He was getting a solid amount of strikeouts at 24.6% but his walk rate which haunted him last year was up to 15.9%. After being picked in the 2022 draft he was injured throughout the entire 2023 season and only pitched twelve games last season. He has a big arm still sitting in the high 90s and topping out at 100 mph. This offseason he’s eligible for the Rule 5 Draft and the Cubs will need to make a decision on the 40 man roster spot because with his big arm he could get picked up by someone. It’ll be a pivotal fall for Wheat. 

Owen Ayers C: The Cubs 19th round pick out of Marshall last season has looked solid at the plate in his first full pro-ball season. In 273 plate appearances he has a .238/.341/.420 slash line with a 126 wRC+. He’s shown a good knowledge of the zone this season with a 11.4% walk rate and has shown some solid pop with 25 extra base hits. He needs to up his contact rate with only a 74.3% but he swings at only 45.8% of pitches. Not a major prospect at this point but some nice tools to build off of. 

Cole Mathis 1B: The Cubs 2nd round pick in last year's draft has been injured for most of his first season. He was recently activated off the injured list on September 6th and only was able to get 128 plate appearances this season. In those he showed the plate discipline and contact ability he was drafted for with a .215/.336/.402 slash line and a 122 wRC+. He’s a very passive hitter, only swinging at 36% of pitches in his last year at the College of Charleston and 37.6% of pitches in Low-A this season. He doesn’t have massive power especially to the opposite field but will spray balls all over and pull homers. He wasn’t able to play a single inning at a position this season only in the lineup as a DH but was regarded as an above average fielder at first base. Will be the best bat for Cubs fans to watch this fall.

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