The Mariners are moving to a six-man rotation, with Bryce Miller set to start the finale against the D-backs and Luis Castillo expected to come out of the bullpen. This move comes as the team begins a stretch of 16 games in 17 days, with the start of their homestand set to take place on Friday. Both pitchers have been criticized for allowing four runs in 17 innings with 21 strikeouts in their two piggybacks.