"It was one of those games where I'm just battling myself out there," Cahill said. "It's been frustrating, since I feel like I've been making strides towards limiting the walks and pounding the zone. And then on a day like this where it all kind of crumbles down. Now you're back to square one. It's not fun when you're kind of fighting against yourself more than the other team."
Cahill struggled badly to open the 2014 season and was sent first to the bullpen and then down to Class A to work on his mechanics and command before being recalled.
Through the first three innings Monday, Cahill had walked four and allowed a hit, but the Padres were unable to push across a run against him.
"When he got ahead, he got in trouble after that because he couldn't put them away," D-backs catcher Miguel Montero said. "He pitched deep into counts all the time. I don't know, I wish I would have the right answer to help him figure out what's going on, because he's got too good of stuff to go four innings with 100 pitches."
Therein lies the D-backs frustration with Cahill -- he possess a nasty sinker and his stuff is good so if he could just get it near the strike zone he could be dominant.
"I think sometimes he tries to be too fine, tries to be too filthy, too nasty and tries to make unhittable pitches when he really doesn't need that," Montero said. "He just needs to throw it right there and get the swings and get the groundball outs. That's all he needs.
"It's just disappointing because I think he's got the best stuff in our rotation overall. He could be pretty nasty if he figures it out because he's got such great stuff. He's got a good sinker, a good changeup, a good curveball and he's unfortunately wasting it."
Cahill is in his sixth big league season, but he is still just 26 years old.
"Sometimes we say, 'When is he going to figure it out? Because he's been here six years in the big leagues,'" Montero said. "But he's still just a baby. We've got to realize that. He's still just  years old, he just got to the big leagues too soon."
In his last start against the Dodgers, Cahill allowed eight runs (six earned) and walked three in 3 1/3 innings. Afterwards he said his arm angle was a little too low, which led to the problems.
It appeared that his arm angle had dipped again Monday.
"Just looking at the pitches, everything was kind of flat and running outside," Cahill said. "I was just kind of aiming middle and trying to get depth on the ball, and it was just running outside and high. I never really got comfortable. From the get-go, I was trying to throw as many strikes as possible. It seems like when I do that, it's the opposite."
The Padres finally broke through against Cahill in the fourth when Alexi Amarista singled home Will Venable to give the Padres a 1-0 lead.
One inning later, Cahill gave up a single and double to open the frame, and Arizona manager Kirk Gibson elected to go to his bullpen.
One out and an intentional walk later, though, rookie Cory Spangenberg drove home a pair of runs with a groundball single to right as the Padres went up, 3-0.
Meanwhile, Padres starter Tyson Ross kept the D-backs off balance through six innings of work.
The lone blemish against Ross came in the sixth when the D-backs led off the inning with three straight singles to pull to within 3-1. Ross, though, was able to settle in as he struck out Jake Lamb, Nolan Reimold and Didi Gregorius to end the inning.