Isaac Mattson
Isaac Mattson
Position: RHP
Height: 6’2”
Weight: 205 lbs
Bats/Throws: R/R
Born: 07/14/1995
College: University of Pittsburgh
Drafted: 19th round, 565th Overall, 2017 (Angels)
How Acquired: Minor League Free Agent
Bonus: $100,000
40-man Roster: No
Rule 5 Eligible: Eligible
Minor League Free Agency: 2024
Options Left: 2
Overview
Mattson was a late-round draftee by the Angels out of Pitt, where he was mainly a reliever. He pitched very well through the low minors, but in AA and AAA after the pandemic season he struggled with control problems. He throws a fastball about 93 mph and adds a curve and change. He’s usually had high K rates and didn’t have control problems until 2022. He hasn’t made any top prospect lists. The Pirates signed Mattson to a minor league deal for 2024.
2017-20
Mattson pitched very well between two rookie levels in 2017, then split 2018 between the two Class A levels. He was a starter at Low Class A, the only time in his career when he’s pitched out of the rotation, then a reliever at High Class A. In the high-offense California League, he managed a 3.62 ERA for a team that overall had an ERA of 5.15.
In 2019, Mattson spent time at the top three levels of the minors, although he put in the bulk of it in AA. He was very successful overall, with a 2.33 ERA, 1.01 WHIP and 13.5 K/9. After the season, the Angels sent him to Baltimore as part of a package for Dylan Bundy. Mattson didn’t pitch during the pandemic season, but the Orioles added him to their 40-man roster that November.
2021-23
Mattson had a difficult time in 2021. He spent the first month of the season at Baltimore’s alternate site and also missed a month late in the year with an injury. He made four appearances in the majors, spread throughout the season, and struggled to throw strikes. He also got hit hard in AAA in 18 games. Despite good walk and strikeout rates — 3.1 BB/9 and 12.5 K/9 — he had a 6.23 ERA.
At the beginning of 2022, the Orioles outrighted Mattson to AAA. He continued to struggle there, walking 20 batters in 17.2 IP. The Orioles released him in July and he caught on with the independent Frontier League. He pitched well there, and also in the first half of 2023 in the Atlantic League. Minnesota signed him to a minor league deal in June and he had a 3.62 ERA with them in AA through the end of the year. The control problems persisted, though, as he walked 24 in 32.1 IP. Mattson became a free agent after the season and signed a minor league deal with the Pirates.
2024
Mattson opened the 2024 season with Altoona and pitched reasonably well over eight games, then moved up to Indianapolis, where he pitched in 29. All of it was in relief except one opener-type start. His performance was about the same at both levels: his walk rate was high, but he also had a good K rate and didn’t give up a lot of hits. Overall, he had a 3.17 ERA, 1.30 WHIP, 4.8 BB/9 and 11.3 K/9. In mid-September, with their bullpen a dumpster fire, the Pirates called him up. He threw five and a third innings, giving up just one hit but walking five.
The Pirates outrighted Mattson to AAA after the 2024 season.
Stats
Transactions
June 14, 2017: Drafted by the Los Angeles Angels in the 19th round, 565th overall pick; signed June 18.
December 4, 2019: Traded by the Los Angeles Angels with Kyle Bradish, Kyle Brnovich and Zach Peek to the Baltimore Orioles for Dylan Bundy.
November 20, 2020: Contract purchased by the Baltimore Orioles.
April 8, 2022: Outrighted to AAA by the Baltimore Orioles.
July 18, 2022: Released by the Baltimore Orioles.
June 22, 2023: Signed as a minor league free agent by the Minnesota Twins.
November 6, 2023: Became a free agent.
December 11, 2023: Signed as a minor league free agent by the Pittsburgh Pirates.
September 19, 2024: Called up by the Pittsburgh Pirates.
November 4, 2024: Outrighted to AAA by the Pittsburgh Pirates.