Pittsburgh Pirates right-handed relief pitcher Isaac Mattson doesn’t bat and thus has never hit for the cycle. But in terms of his Pittsburgh bona fides, the 30-year-old has pitched for the cycle. The Erie, Pennsylvania native pitched for the University of Pittsburgh from 2015-17, the Washington Wild Things, a Frontier League team located 45 miles southwest of Pittsburgh, in 2022, and the Pirates in 2024 and 2025.
Isaac Mattson Could Step In as Pirates Closer
Last month, the Pirates traded David Bednar, who had been their closer since 2022. Dennis Santana has since taken over the role, a job for which he auditioned earlier in the year when Bednar was sent to Triple-A. Santana has performed admirably in the role. He’s 4-5 with 13 saves, a 2.40 ERA, 3.22 FIP, and 0.917 WHIP going into Thursday’s schedule. His 2.1 WAR leads all Pirates pitchers not named Paul Skenes.
That said, it’s not a far-fetched notion that Santana could be traded after the season. The Pirates’ deadline deals pared payroll so that general manager Ben Cherington – or his successor if he’s fired – could add some much-needed hitters. Now the trick is to sign those hitters on the free agent market. It won’t be an easy trick. Cherington recently said on the MLB Trade Rumors podcast that it’s difficult to get free agents to come to Pittsburgh. Steelers coach Mike Tomlin often says he wants “volunteers, not hostages.” Not finding volunteers, Cherington may have to trade for hostages. He’ll have to give up good players to get good players. That might mean dangling Santana in front of potential trade partners. (Cherington has largely failed at acquiring hitters, but that’s not today’s topic.)
Enter Mattson
That brings us to Mattson. The Pirates recalled him from Triple-A Indianapolis on May 20. He’s pitched like he doesn’t want to go back. Working his way into a high-leverage role, he’s 3-2 with a 2.31 ERA, 3.14 FIP, 1.026 WHIP, and nine “holds.” Opponents have been held to a .193/.266/.293 slash line. Mattson has solid strikeout and walk rates of 26.4 and 8.2 percent, respectively. He relies on a four-seam fastball, which he throws 77.1 percent of the time. Averaging 94 mph, it generates a 27.8 percent whiff rate. He also throws a slider, curve, and, less frequently, a changeup.
3 years ago, Isaac Mattson was pitching for the Washington Wild Things, an independent baseball team
Tonight, he catches Shohei Ohtani in a pickle to get him out pic.twitter.com/d3qccyprO8
— Platinum Key (@PlatinumKey13) September 3, 2025
Before joining the Pirates (and the Wild Things), his major league experience consisted of 4 1/3 innings with the Baltimore Orioles in 2021, during which he gave up three earned runs. With the Pirates briefly last year, Mattson surrendered three more earned runs in 5 1/3 innings. So, did the light suddenly come on for Mattson in 2025? He had good minor league statistics until 2021, when he posted a 6.23 ERA for Triple-A Norfolk. When he followed that up with a 6.62 ERA at Norfolk by July 2022, he was released by Baltimore and landed with the Wild Things. After spending 2023 in the Minnesota Twins system and then with another independent league team, the Pirates signed Mattson as a minor free agent for the 2024 season. In more than one interview, Mattson credited becoming a father in 2025 for his success. It does make a guy more serious.
The Last Word
So, we return to the notion that Santana could be traded to acquire offense. It makes sense, given that the Pirates will be dealing from strength. They’ve also done well under Cherington, developing relief pitchers that they pick up from baseball’s scrap heap. Can a 30-year-old journeyman who suddenly found success in 2025 become a major league closer in 2026? This writer has always thought that the modern belief that it takes a special talent or makeup to pitch in the ninth inning with a lead is nonsense. When a pitcher has put in the work, persevered to the point where he went to the Frontier League, and made it to the big time, it defies logic that he’d wet his pants over the prospect of a save situation.
Furthermore, baseball history is full of tales of closers who didn’t fit the profile at first. Generally, closers aren’t developed. They just “happen.” For example, Kent Tekulve, the Pirates’ bullpen ace when they won the 1979 World Series (nobody called them closers back then), was cut from his high school team. All he did was save 184 games in the majors. It will be interesting to see whether the Pirates ever give Mattson the opportunity.
Main Photo Credit: © Charles LeClaire-Imagn Images
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