Diaz (back) notched his 31st save with a clean ninth inning in Friday's 3-2 win over the Athletics, recording one strikeout.
Diaz had been bothered by back spasms in recent days according to manager Scott Servais, but he appeared to be at full strength while disposing of Ryon Healy, Bruce Maxwell and Matt Chapman on 15 pitches. The 23-year-old has put together four straight scoreless appearances -- which have all resulted in saves -- after allowing three earned runs over 1.2 innings across two outings in mid-August.