Rivas is slated to start at shortstop for the Mariners on Opening Day after J.P. Crawford (shoulder) was placed on the 10-day injured list, Adam Jude of the Seattle Times reports.
The Mariners might have considered top prospect Colt Emerson to play shortstop if Crawford's absence was going to be an extended one, but he's expected back in a couple weeks. As such, the club will turn to the defensively gifted Rivas at shortstop. Rivas has a good eye at the plate, but he's unlikely to be worthy of a roster spot in fantasy leagues even while playing regularly.