Thaiss will start at catcher and bat eighth in Wednesday's game against the Mariners.
Thaiss will step in behind the plate for the series finale while top backstop Logan O'Hoppe rests for the day game after catching all nine innings of Tuesday's 5-1 win. Expect Thaiss' opportunities to remain fairly limited moving forward while O'Hoppe continues to handle one of the heavier workloads among all catchers.