Miller earned the save in Wednesday's 5-2 win over the Mariners, allowing one hit with two strikeouts in a scoreless ninth inning.
Miller was summoned to protect a three-run lead in the ninth and needed just 14 pitches to do so. The 34-year-old has held opponents scoreless in nine of his past 10 appearances, converting four of five save chances during that stretch. He owns a 1.63 ERA, 1.08 WHIP and 29:11 K:BB across 27.2 innings this season and should be the favorite to close games for the Diamondbacks with Justin Martinez (elbow) back on the injured list.