"He's made a nice impression here, there's no denying that," Twins manager Paul Molitor said. "He definitely knows how to pitch a little bit. He's had experience. He's focused. He's making a run for it, that's for sure."
Boyer, 33, posted a 3.57 ERA with the Padres last year, striking out 29 and walking eight in 40 1/3 innings. It was his first season in the Majors since 2011 after a brief retirement and a stint pitching in Japan in '13.
"I've been through a lot of these and I feel good," said Boyer, an eight-year veteran who has pitched for the Braves, Cardinals, D-backs, Mets and Padres. "At this point, you look back at what I did last year, and they know what I can do. It's just them having to make one decision or another. But I think they know what they have in me."
One new wrinkle for Boyer is the addition of a changeup this spring with the urging of pitching coach Neil Allen. Boyer said he didn't throw any changeups last year, as he was mostly a fastball-cutter pitcher with an occasional curveball. Boyer held right-handers to a .178/.219/.289 line last year, but lefties hit .305/.339/.475 against him. So he's hoping the changeup will help neutralize lefties, but the pitch remains a work in progress.
"Neil got me this grip I really like," Boyer said. "I'd love to get a bullpen or two with it. It's a great pitch. It's a really good pitch for me, and so I'm excited to implement that. But it's kind of tough to when you're battling to show what you can do to mess around with a pitch."
With Glen Perkins, Casey Fien, Brian Duensing and Tim Stauffer considered locks, the Twins have three spots in the bullpen open, but it could be two if the Twins decide to move Mike Pelfrey or Tommy Milone to the 'pen. Other candidates for those spots are Caleb Thielbar, A.J. Achter, Aaron Thompson, Stephen Pryor, Rule 5 Draft pick J.R. Graham and fellow non-roster invitee Mark Hamburger.
Molitor said he hopes to make his decision on the bullpen by next weekend, which will give Boyer time to decide whether to invoke his opt-out clause on March 30 if he doesn't make the roster.
Rhett Bollinger is a reporter for MLB.com. Read his blog, Bollinger Beat, and follow him on Twitter @RhettBollinger. This story was not subject to the approval of Major League Baseball or its clubs.