Just days after Diamondbacks’ starting pitcher Trevor Cahill had a rough outing for Triple-A Reno in his second rehab start, he threw a phenomenal bullpen session at Chase Field on Wednesday.

It was so good, in fact, manager Kirk Gibson was raving about it in his pregame media session before playing the Rays.

“He threw the ball great in his bullpen, he really did,” Gibson said. “I just said, ‘how do you give up six runs with that?'”

Cahill surrendered six earned runs, including back-to-back home runs, on six hits with six strikeouts in 4.1 innings of work in a 7-3 loss to New Orleans on Monday.

“I mean I stood in there on him and he’s been working on getting his arm up higher and he said he could feel his arm getting down,” Gibson stated. “He’s not used to throwing so many pitches from that slot and he just couldn’t get control of it.”

Cahill went on the 15-day disabled list on July 1 with a right hip contusion, but he struggled even before the injury.

In 17 starts in 2013, the right-hander is 3-10 with a 4.66 ERA. The 25-year-old is 16-22 with a 4.07 ERA in 49 starts since joining the D-backs in 2012.

On Wednesday, Gibson was asked if changing a pitcher’s arm slot in the middle of the season is unusual.

“I don’t think so. I mean he just got down there so low that he really couldn’t control things and just is not consistent with it,” Gibson explained. “That’s why he’s always struggling to find the strike zone. One time the ball moves, one time it doesn’t move.

“These guys try and find a place where the ball is coming out the same way for the hitter but it does different things. Like I said, he threw great.”

Cahill has 39 walks on the season and 69 strikeouts in 96.2 innings of work. His location has been a constant battle this season.

Gibson also said his short and less than stellar start on Monday with Reno was due to fatigue. Cahill got tired and was only able to pitch into the fifth inning. The D-backs’ manager said Cahill would need to be stretched out further.

Despite a good bullpen session on Wednesday, Gibson still feels it’s important for Cahill to get another rehab start with Triple-A, likely on Saturday.

“He’s probably going to throw another game in the minor leagues on his regular day,” Gibson said.

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