D-backs firm up front of rotation, but several spring battles unresolved


SCOTTSDALE, Ariz. -- Diamondbacks manager Kirk Gibson confirmed Wednesday that Brandon McCarthy will start the team's home opener at Chase Field on Monday and laid out the front end of the rotation to start the season.
Wade Miley and Trevor Cahill will follow McCarthy on Tuesday and Wednesday, respectively, but Gibson said the back end of the rotation remains unresolved.
First-year D-back Bronson Arroyo is likely to start either the series finale against the Giants or the first game of a three-game series in Colorado, but the D-backs want to see how he has progressed in recovering from a bulging disc in his back.
"I expect him to be ready," Gibson said. "It's a matter of when. Is it the fourth game? Is it the first game in Colorado? Unless he has a severe setback, I expect him to be ready for one of those games."
Arroyo is set to pitch Saturday in an afternoon exhibition against the Cubs at Chase Field in what will be his second spring training start.
The fifth rotation spot, Gibson said, remains unsettled. Gibson and general manager Kevin Towers were to discuss on Wednesday the decision between Randall Delgado, Bo Schultz and top prospect Archie Bradley.
It is presumed Delgado will be the choice to take the spot opened up when ace left-hander Patrick Corbin suffered a partially torn ulnar collateral ligament in his elbow that required Tommy John surgery. Bradley and Schultz would then begin the year with Triple-A Reno.
"We have until the end of the week," Gibson said. "We'll have guys throwing various places this week."
Delgado is scheduled to start in one of two split squad games Thursday, while Schultz and Bradley were expected to pitch in minor-league games.
McCarthy, who didn't travel to Australia for the D-backs season-opening series with the Dodgers, has been a bright spot among D-backs pitchers this spring. Entering his start Wednesday, he owned a 1.93 ERA, having given up three runs on three hits over 14.0 innings.
"He's throwing good," Gibson said. "His curveball's been better this year, he's used his cutter a lot smarter so far. But he hasn't had a lot of pressure so far."
The D-backs have more decisions to make over the next few days than the final spot in the starting rotation. Still undecided -- or at least unannounced publicly -- are the battles for the starting job at shortstop and backup catching job.
"I think it's unresolved at this point," Gibson said. "We have some time. You like to make decisions, but that one I think is just going to play out a little longer."
The recent perception, fueled by unconfirmed trade rumors regarding Didi Gregorius, is that Chris Owings has won the starting job at shortstop. Less clear is the competition to back up Miguel Montero between Tuffy Gosewisch and Henry Blanco, who is expected to become the D-backs assistant hitting coach should Gosewisch win the job.
Gibson returned to action at Salt River Fields on Wednesday after his absence Tuesday to have arthroscopic surgery on his left knee.
Gibson, on crutches for the next few days, did not sit in the dugout for Wednesday's game against the Cubs but is expected to be back on the bench Thursday.
"I feel great, a lot better than I did," Gibson said. "It was something I needed to get taken care of, so it was good."
Gibson said the achy knee had bothered him all spring but got drastically worse about a week before the trip to Australia. Knowing he couldn't have anything done before the trip, Gibson set the matter aside until the team returned. He had an MRI on Monday, followed by the brief procedure on Tuesday.
"I would've never made it through the season that way," Gibson said.
Gibson said Wednesday he has been in contact with Corbin, who had Tommy John surgery Tuesday at Dr. James Andrews' clinic in Pensacola, Fla.
"I think he's in a better spot." Gibson said. "When he was here before we left, it was crushing. Here he thought he was getting ready to go start and prepared hard to start in Australia and that was taken from him.
"I'm sure he partly felt like he was letting us down, which he wasn't. It happens. He gave us everything he had."
Corbin is expected back in Arizona for Opening Day at Chase Field, Gibson said, and will likely remain around the team as Daniel Hudson has while rehabbing from two Tommy John surgeries the past two seasons.
The D-backs' medical staff had recommended Tommy John surgery to Corbin before his second opinion, so the team had prepared mentally for the possibility of being without him the entire season.
"We kind of thought it was going to be something more on the 'need to get it repaired' side, but it's the player's choice," Gibson said. "What we saw, we probably thought that's what the second opinion would say, but we didn't tell him that. ... He went down there, and once that happened he pretty much decided right away he wanted to have it. Usually when guys go down to Andrews, that's what happens."
Follow Tyler Lockman on Twitter