A's closer Blake Treinen did not cap off his career year with the AL Reliever of the Year Award, missing out as Seattle Mariners closer Edwin Diaz won the honor.
Treinen, one of three finalists, was named an All-Star for the first time in his career in 2018. He finished the season with a career-high 38 saves and a career-low 0.78 ERA and 0.834 WHIP.
The margins were razor-thin between him and Diaz. Diaz also made an All-Star game for the first time in his career, saving 57 games for the Mariners and posting a 1.96 ERA and 0.791 WHIP. His FIP (1.61) was slightly better than Treinen's (1.82), and he also struck out more batters per nine innings (15.2 vs. 11.2).
Former A's relievers Dennis Eckersley and Rollie Fingers were among the eight, all-time greats that formed the voting panel for the award.