Isaiah Campbell

Isaiah Lyn Campbell (born August 15, 1997) is an American professional baseball pitcher for the Boston Red Sox of Major League Baseball (MLB). He has previously played in MLB for the Seattle Mariners. Campbell was selected by the Mariners in the second round of the 2019 MLB draft.

Amateur career
Campbell was born in Portugal, where his father was stationed while serving in the United States Air Force, but grew up in Kansas and attended Olathe South High School in Olathe, Kansas. As a senior, he compiled a 5–1 win–loss record with a 1.66 earned run average (ERA). He struck out 42 batters in $33 2⁄3$ innings pitched.

Campbell made six starts and 13 appearances for the Arkansas Razorbacks as a true freshman. He had 23 strikeouts in $31 2⁄3$ innings pitched while going 3–1 with a 3.69 ERA. He was also named to the Southeastern Conference (SEC) First Year Academic Honor Roll. His sophomore season in 2017 was cut short after just $2⁄3$ of an inning due to an elbow injury, for which he was granted a medical redshirt. He helped the Razorbacks to the 2018 College World Series final, winning the game in the semi-final that allowed them to advance to the final. That season, he appeared in 18 games, making 17 starts, including four in the NCAA tournament and two in the College World Series.

After the 2018 season, Campbell was drafted by the Los Angeles Angels in the 24th round of the 2018 MLB draft, but opted to return to college for his junior season. In 2019, he had his best season yet, making 18 starts, striking out 125 batters in $118 1⁄3$ innings and going 12–1 with a 2.13 ERA. The Razorbacks reached the 2019 College World Series but were eliminated in the first round by Florida State.

Seattle Mariners
Campbell was selected by the Seattle Mariners in the second round of the 2019 MLB draft. Campbell signed with the Mariners for an $850,000 signing bonus. He did not play professionally that season, and did not play a minor league game in 2020 due to the cancellation of the minor-league season caused by the COVID-19 pandemic.

Campbell made his professional debut in 2021 with the Everett AquaSox of High-A West, pitching $19 1⁄3$ innings and going 3–1 with a 2.33 ERA. His season ended prematurely after undergoing elbow surgery. He began the 2022 season as a starting pitcher, but continued to experience elbow discomfort after his first four games, and he was placed on the injured list again. After Campbell's return, the Mariners converted him to a relief pitcher to minimize the stress on his elbow, and Campbell thrived in his new role, giving up only an unearned run on eight hits and a walk while striking out 20 in 15 innings for the AquaSox. This performance earned Campbell a promotion to Double-A with the Arkansas Travelers in August. With Arkansas in 2022, he pitched to a 3.46 ERA and struck out 24 batters while walking only two.

Campbell was optioned to the Double-A Travelers to begin the 2023 season. In 23 games to begin the season, he went 6–0 with a 2.63 ERA, 27 strikeouts, and 2 saves in 24.0 innings of work. On July 6, 2023, Campbell was promoted to the major leagues for the first time. He made his debut on July 7 by throwing a scoreless inning with one strikeout. This made Campbell only the second Portuguese-born player to appear in the major leagues, and the first since Frank Thompson, who played twelve games in 1875. After making three appearances in total and recording six strikeouts, Campbell was sent back down to Double-A on July 19. He was called back up three days later, and garnered his first major league victory against the Toronto Blue Jays. Overall, Campbell appeared in 27 major-league games with the Mariners, all in relief, compiling a 4–1 record with a 2.83 ERA and one save.

Boston Red Sox
On November 17, 2023, Campbell was traded to the Boston Red Sox in exchange for infielder Luis Urías.