PEORIA, Ariz. -- In the second surprise of Mariners camp, left-hander Ariel Miranda was optioned to Triple-A Tacoma on Saturday as the club intends to keep him stretched out as a starting option rather than open the season as a second lefty in the bullpen.
Catcher Sebastian Valle was also reassigned to Minor League camp, leaving the Mariners with 41 players in Major League camp as they approach next week's final cutdown to 25 prior to Opening Day on April 3.
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The Mariners sent rookie Daniel Vogelbach, who was expected to be the starting first baseman, down to Triple-A earlier in the week to give him more developmental time.
Miranda came to camp as the Mariners' sixth starter, with the belief he'd move to the bullpen if needed. But the 28-year-old Cuban will remain in a starting role in Triple-A Tacoma to start the year. He went 5-2 with a 3.54 ERA in 11 games (10 starts) last year after being acquired from the Orioles for Wade Miley on July 31.
"Looking where we're at, it might be best to keep him stretched out," manager Scott Servais said. "Coming into camp, unless we had an injury with our original starting five on paper, it was going to be very difficult for him to make the team.
"We're pretty healthy, knock on wood, with those five, so we'll try to keep him stretched out if we can and be in a situation where if we needed help at some point, he'd be available for us as a rotation piece."

The Mariners' starting five will be Felix Hernandez, Hisashi Iwakuma, James Paxton, Drew Smyly and Yovani Gallardo.
Miranda's departure opens the door for a second lefty in the bullpen behind veteran Marc Rzepczynski, with James Pazos, Dillon Overton and veteran non-roster invitee Nick Hagadone the likely options unless general manager Jerry Dipoto adds another candidate in the final week.
"We've got other guys," Servais said. "We're trying to do what's best for Miranda and how he fits into our plans. I think Ariel fits best as a starter. So that's the decision we made and we'll keep him in that role in Tacoma to start out."
Miranda had a 6.14 ERA in six games (five starts) in Cactus League play and took the loss after allowing four runs (three earned) in four innings in his last start, Friday's 4-0 loss to the Angels.
"Ariel did a great job for us last year, there's no doubt, and he's definitely going to impact us at some point this year," Servais said. "Where we're at moving forward in the last week, there's not a start for him in this camp, so we'll put him on the Minor League side, keep him going and keep his pitch count up. We're probably going to need him at some point, and I'm very comfortable going to him."
Valle, 26, was signed as a Minor League free agent in December and saw limited time this spring, going 1-for-4 in three games. He played for Team Mexico in the World Baseball Classic.