SF@ARI: Gibson breaks down Cahill's performance

SAN FRANCISCO -- On the heels of a disappointing beginning for their starting pitchers, the D-backs are pondering possible changes in their rotation.

In an effort to get Josh Collmenter stretched out, D-backs manager Kirk Gibson had him throw four innings in relief against the Giants on Wednesday night. That leaves Collmenter in position to start next week if needed.

"We've had discussions," Gibson said. "Obviously things have not been going as we planned. We're better than this and we can't keep going on in this fashion. Nothing is concrete at this time. We'll continue to talk about it. We'll get through this road trip and we'll probably talk about it on a daily basis. Obviously we want to try to make it better. We need to get more innings out of our starters, No. 1."

The two pitchers most in jeopardy of losing their spots are Randall Delgado and Trevor Cahill.

Delgado, who is set to start Thursday night against the Giants, allowed six runs over 4 2/3 innings in his lone start this year.

Cahill has made three starts, including one in Australia against the Dodgers, and has a 7.90 ERA.

Of even greater concern is the lack of innings Cahill has been able to pitch, as he has gone four, six and 3 2/3 in his starts. That puts a strain on the bullpen, and it is a situation the D-backs seem unlikely to tolerate much longer.

The D-backs have seen some positives in Cahill, making Delgado's start against the Giants on Thursday a crucial one for him.

"We see some things that he's improving in," Gibson said of Cahill. "The results are not one of them, but as of right now, we expect him to make his start."

The D-backs also have options in the Minor Leagues, with Bo Schultz, Archie Bradley and Mike Bolsinger among them, but Gibson seems to be leaning toward Collmenter at this point if a change is made.

Collmenter happy to pitch wherever needed

ARI@SF: Collmenter gets double play to end game

SAN FRANCISCO -- D-backs right-hander Josh Collmenter said he is ready and willing to step into the starting rotation if the team decides to make a change with one of its slumping starters.

However, Collmenter has grown quite comfortable in the bullpen after moving there from the rotation in 2012.

"A couple of years ago I probably would have been more ecstatic, but I've grown to like the bullpen, just the variety of roles you get used in," Collmenter said. "It's definitely closer to an equal in terms of the likability of each role, but if that's where the team wants me, that's absolutely where I'll be."

D-backs manager Kirk Gibson said the team is considering shifting Collmenter to the rotation if starters like Randall Delgado and Trevor Cahill continue to struggle.

Though he has not started a game since 2012, Collmenter had several long stints out of the bullpen last year, including a six-inning one against the Marlins in June. His ability to get stretched out quickly has long been an asset for him.

Collmenter worked four innings and threw 55 pitches in relief Wednesday night against the Giants, which should put him in position to be an option for the rotation next week if the club decides to add him.

"I got stretched out a decent amount in Spring Training," Collmenter said. "A couple of three-inning outings or at least throwing parts of three innings, so it wouldn't take long. That's kind of the nice thing about how my arm works; it doesn't take too long to get there. So maybe one three-inning outing, I'm sure I could go five, no problem."

Ziegler sees results of work on mechanics

Brad Ziegler chats with Christopher Russo

SAN FRANCISCO -- Brad Ziegler tossed a 1-2-3 inning Tuesday afternoon against the Giants, which seems simple enough, but there was a lot of work that went into it before that.

"I've been working my tail off the last four days before that trying to get my delivery back to being repeatable," Ziegler said. "I felt like it was pretty good in Sydney and then when I came back everything was kind of out of whack again. One way or another, my arm slot wasn't right, the direction of my body wasn't right. Everything was kind of spinning instead of driving toward the plate."

Ziegler blew a save against the Giants on March 31 when he walked in a run, and he allowed a pair of runs last weekend in a one-inning stint in Colorado.

"Ziegler's outing was encouraging," Gibson said of Tuesday's appearance.

Ziegler is taking nothing for granted at this point.

"I've been around long enough to know that one outing doesn't fix everything," he said. "I've got to continue it and make it to where it's habit and to where I don't have to think about it while I'm out there."