"He pitched outstanding baseball at Double-A, getting big outs at the ends of games," Twins manager Paul Molitor said. "He's not a left-on-left specialist, per se. He's a guy who knows how to pitch with passion and energy. His numbers jump off the page."
Moya made his MLB debut in Tuesday's 16-0 win over the Padres, pitching a scoreless ninth inning.
Moya, 22, doesn't have top velocity, with a fastball ranging from 90-92 mph, but his strength is locating his pitches and mixing speeds. His best pitch is his changeup, and he also has a slider. He actually had better numbers against right-handers, holding them to a .121/.178/.156 line, while lefties hit .220/.292/.356 against him.
"He's just another option for us," Molitor said. "I'm not sure how we're going to find a spot for him yet exactly. We've got 14 choices down there. So, we'll see how it plays out, but congratulations to him being part of the big leagues here."
The decision to designate Vielma was a bit surprising, as the Twins view him as a plus defender at shortstop, but concerns about his offense intensified with a rough year at Triple-A Rochester this season. Vielma hit .206/.233/.260 with no homers, 12 doubles and two triples in 87 games at Triple-A. There remains a chance he could remain in the organization if no other club claims him off waivers.
• Third baseman Miguel Sano (left shin stress reaction) took early batting practice on the field before Tuesday's game against the Padres, but didn't participate in running drills after running on Monday. Molitor said Sano is inching closer to a return, but when asked if Sano was a week or so away, Molitor said there remains no timetable. Sano will meet with team doctors Tuesday night to get reexamined.
• The Twins have yet to name a starter for Thursday's series opener against the Blue Jays. Right-hander Jose Berrios could start on regular rest, or left-hander Adalberto Mejia could be activated from the 10-day disabled list to start.
Rhett Bollinger has covered the Twins for MLB.com since 2011. Follow him on Twitter @RhettBollinger and Facebook. This story was not subject to the approval of Major League Baseball or its clubs.