LAA @ PITFinal 6-1, Sep 5, 2026
IP 2.0, H 4, R 3, ER 3, BB 0, K 2, HR 0, PC-ST 39-28, ERA 5.35, PC 39
Betting: PIT moneyline lost, run line -1.5 did not cover
BaseballMLBSeattle MarinersRelief pitcher
Isaac Mattson
Stats, career and game logIsaac Mattson is a relief pitcher for the Seattle Mariners, and through the 2025 season he had a 2.98 ERA over 51 games.
89 MLB games90 strikeouts
Updated
About Isaac Mattson
Born on July 14, 1995, in Erie, Pennsylvania, Isaac Mattson is a relief pitcher for the Seattle Mariners, wearing number 72. He played college baseball for the Pittsburgh Panthers, and he bats and throws right-handed.
Mattson made his MLB debut on May 7, 2021, with the Baltimore Orioles. In the 2025 regular season he pitched in 44 games for the Pittsburgh Pirates with a 2.45 ERA and 45 strikeouts in 47.2 innings. Through the 2025 season, he had a 2.98 ERA and 54 strikeouts in 57.1 innings over 51 games.
Agatha Research DeskUpdated Nov 3, 2026Season by season89
Every season, every MLB appearance of his career, newest season first.
| Season | Team | Games | Starts | IP | K | BB | ERA | WHIP |
|---|---|---|---|---|---|---|---|---|
| 2026 |  PIT | 38 | 0 | 38.2 | 36 | 18 | 5.35 | 1.60 |
| 2025 | PIT | 44 | 0 | 47.2 | 45 | 19 | 2.45 | 1.13 |
| 2024 | PIT | 3 | 0 | 5.1 | 6 | 5 | 5.06 | 1.12 |
| 2021 |  BAL | 4 | 0 | 4.1 | 3 | 5 | 6.23 | 2.31 |
| Career | 89 | 0 | 96.0 | 90 | 47 | 3.94 | 1.38 |
How he is doing now
2026 pitching5.35 ERA38.2 innings, 36 strikeouts, 1.60 WHIP
Mariners76-862026 regular season
Last game2.0 IP, 2 K, 3 ERSep 5 vs Angels
Injury status
No active flag. Latest report 15-Day-IL (64d ago), no longer on the injury report.
Game log, 2026
DET @ PITFinal 8-5, Aug 17, 2026
IP 2.0, H 2, R 1, ER 1, BB 2, K 1, HR 0, PC-ST 41-24, ERA 4.91, PC 41
Betting: PIT moneyline lost, run line +1.5 did not cover
Box score lines from ESPN.
Betting: his team's result at the closing moneyline and run line most of our sportsbooks closed at (3 books or more).
Career
5years2021 to 2026
- 2021MLB debutBaltimore Orioles
- 2025Best season47.2 IP, 45 K, 2.45 ERA in 44 games
- Sep 5, 2026Latest game2.0 IP, 2 K, 3 ER vs Angels
Regular season
89 games
96.0 IP, 90 K, 3.94 ERA
MLB debut
2021 seasonBaltimore Orioles
Latest game
Sep 5, 2026: 2.0 IP, 2 K, 3 ERAngels 6, PIT 1
Most often against
The teams he has faced most, with his teams' record and his line against each.
Milwaukee Brewers11 games
6-5his teams
His line: 11.2 IP, 12 K, 3.09 ERA
Last met Jul 12, 2026
Cincinnati Reds9 games
3-6his teams
His line: 9.2 IP, 9 K, 0.93 ERA
Last met Jun 27, 2026
Chicago Cubs7 games
3-4his teams
His line: 8.2 IP, 4 K, 4.15 ERA
Last met Jul 25, 2026
St. Louis Cardinals6 games
4-2his teams
His line: 5.0 IP, 4 K, 9.00 ERA
Last met Apr 30, 2026
Washington Nationals5 games
1-4his teams
His line: 7.1 IP, 4 K, 4.91 ERA
Last met Jul 5, 2026
Philadelphia Phillies4 games
1-3his teams
His line: 4.0 IP, 3 K, 0.00 ERA
Last met Jun 30, 2026
Injury history
ESPN's injury reports, newest first.
- Sep 8, 202615-Day-IL Hip
The Pirates recalled Mattson from Triple-A Indianapolis on Friday, Danny Demilio of PittsburghBaseballNow.com reports.
ESPN / PIT
Sources and updates
Stats, scores and injury reports come from Agatha's own records: the SABR Lahman Baseball Database for the seasons through 2025, MLB's own box scores, its transactions and ESPN's injury reports.
Updated Nov 3, 2026, 7:57 PM ET. Results and form refresh after every game; biography facts are checked weekly.