Photo provided by Matt Lynch
This is one in a series breaking down players on the Pittsburgh Pirates’ 40-man roster.
Isaac Mattson has to wait three years for his second chance in the big leagues.
The right-hander first debuted with the Baltimore Orioles in 2021, when he made made four appearances and allowed three runs.
After making pit stops pitching in the minor leagues for the Orioles, Minnesota Twins and even the Washington Wild Things in the Independent League, Mattson signed a minor-league contract with the Pirates ahead of the 2024 season.
Mattson pitched well with Triple-A Indianapolis and made his awaited return to a big-league mound. He made three appearances with the Pirates that year and allowed three runs on one hit with five walks and six strikeouts.
Mattson remained with the Pirates for the 2025 season and began the year back at Triple-A. But he was promoted to Pittsburgh on May 20, and despite being sent back down briefly later in the month, spent the rest of the season in the big leagues.
Not only did the 30-year-old get used heavily by manager Don Kelly, but he was extremely effective and became an unexpected leverage option late in games and in big spots.
Mattson totaled 44 appearances out of the bullpen for the Pirates on the season and went 3-3 with a 2.45 ERA. He held opponents to a .203 batting average and a .600 OPS, walked 19 and struck out 45.
A product of the University of Pittsburgh, Mattson’s success with the city’s big-leagues team has him poised to once again be a key component of the bullpen in 2026.
The Pirates have added a pair of left-handers into the mix in Gregory Soto (signed as a free agent) and Mason Montgomery (acquired from the Tampa Bay Rays), but could still be looking for a right-handed leverage option. If they are unable to bring another back-end option into the mix, Mattson could be viewed as someone who can be used even more in that role.
Even if the Pirates to add another leverage reliever, Mattson could again find handling the big moments if he’s able to replicate his success this coming season.
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