Dunn tossed two scoreless frames as Seattle's opening pitcher and didn't factor into the decision in Tuesday's 3-0 loss to the Astros. He gave up a base hit and struck out one in the 27-pitch outing.
After a rough big-league debut Sept. 12 in which he walked five batters and failed to escape the first inning, Dunn has now kept the opposition off the board in back-to-back turns as opener. The rookie is scheduled to make his final appearance as an opener Sunday against Oakland, likely working in front of primary pitcher Tommy Milone in the contest.