Bolsinger called up to take Cahill's rotation spot

PHOENIX -- In an effort to shake up their struggling starting staff, the D-backs selected the contract of right-hander Mike Bolsinger from Triple-A Reno and optioned right-hander Will Harris to Reno.

Bolsinger, who was 2-0 with a 1.42 ERA in two starts for Reno, made his big league debut by tossing three innings of two-run ball Monday against the Mets in relief of Josh Collmenter, and he will take the rotation spot of Trevor Cahill starting Saturday against the Dodgers in Los Angeles.

Bolsinger, 26, is not overpowering with a fastball in the 88-91-mph range. He throws a cut fastball as his primary pitch and also has a good curveball, while his changeup is still a work in progress.

"I throw a cut fastball like Mariano Rivera," Bolsinger said. "Not as good, obviously -- I wish it could be -- but really that's what I pitch off of and I have a curveball, too, but really I try to establish my fastball and it's been getting a lot of groundouts, so I'm going to keep going with that plan. It's been working in Triple-A. I know this is the big leagues, but just keep going with what's working for you. I'm not going to be the guy that's going to throw 95 past you. I'm going to try and outsmart you on the mound and hit my spots."

Bolsinger was drafted by the D-backs in the 15th round of the 2010 First-Year Player Draft. He was never at the top of any prospect lists, but continued to put together solid outings.

"I've not ever not seen this guy pitch well," D-backs general manager Kevin Towers said, adding that Bolsinger was a strike thrower with "no fear."

One of the biggest improvements that Bolsinger made this year was throwing the ball inside more. That was something he was uncomfortable doing in the past.

"Before the year started, I talked to my dad and I was like, 'I'm just going to kind of let loose this year and blow it all out,' and that's what I've been doing, so hopefully I can keep doing that," Bolsinger said.

Harris had struggled with a 9.72 ERA in seven relief appearances this year and was one of the few relievers that still had Minor League options remaining.

As for those calling for the D-backs to promote top prospect Archie Bradley instead, Towers said that he felt Bradley needed some more time at Triple-A and did not want to cast him in the role of savior for a struggling team.