Peterson allowed three runs (zero earned) on four hits and no walks while striking out three over five innings in Sunday's 5-1 loss against the Diamondbacks.
Peterson was mostly effective in bulk relief, entering in the third inning and running into little trouble until the sixth, when he allowed three unearned runs following an Andy Ibanez throwing error to open the frame. The southpaw has shown slight improvement over his past two outings, but his season numbers remain underwhelming, as Peterson owns a 5.49 ERA and 1.50 WHIP across 39.1 innings. His next outing is tentatively lined up for Saturday against the Yankees and will likely come behind an opener once again.