Rivas started at shortstop in Sunday's win over the White Sox, going 0-for-4 with an RBI fielder's choice.
The 26-year-old saw time as a late-inning defensive replacement in the opening game of the series Friday, but he did not log a plate appearances. Sunday's start therefore marked Rivas' first encounter with big-league pitching since way back on May 9, and the he managed to contribute the Mariners' third run of the afternoon with his third-inning groundout. With J.P. Crawford (finger) projected to be sidelined up to six weeks, Rivas should continue seeing occasional opportunities in the infield.