PHOENIX -- Madison Bumgarner tried to answer the questions posed to him Monday night, but if the left-hander actually knew why he's struggled so much this year, well, he'd surely fix it.

But he doesn't know, so he keeps searching -- looking at the data, looking at video, taking direction from his coaching staff.

So far, nothing has really clicked. Monday was more of the same for Bumgarner, who allowed six runs over 4 2/3 innings as the D-backs fell, 9-5, to the A's at Chase Field.

In three starts this year, Bumgarner has thrown 13 2/3 innings and allowed 33 baserunners while compiling an 11.20 ERA.

"I don’t know, a little bit of everything here and there, it just depends on which game you point at," Bumgarner said when asked what he thought was behind his struggles this season. "Nothing has been consistent for me. I haven’t been able to get ahead of guys, put guys away. [I've been] throwing a lot of pitches, getting behind too much."

Following his start Monday, Bumgarner was asked how he would describe the frustration he feels.

"I wish I had the words to tell you that for myself, but I don’t have them," he said. "I don’t know what to say. It’s extremely frustrating is not -- that doesn't do it justice. I’m trying everything I can think of. We’re doing the best we can. It is tough. It’s not a very fun game for me right now. We’re trying to do what we can to get things rolling."

Last season, his first in Arizona after signing a five-year, $85 million free-agent deal, Bumgarner struggled to the tune of a 6.48 ERA in nine starts.

At the time, the reason seemed easy to diagnose -- his average fastball velocity had dipped to the lowest of his career, something the team believed was attributable to the normal season ramp-up, the abrupt pandemic shutdown and then another quick ramp-up to the modified, 60-game season.

And when Bumgarner's velocity appeared better this spring, there was cause for optimism. At times during these three starts there were signs -- a good curveball, or better location -- that provided hope, albeit short-lived.

"I feel like -- I’ve felt like this for a while -- but I feel like I’m just about to kind of cross that mountain, or get to the other side and have a breakthrough and so far it hasn’t happened," Bumgarner said. "I don’t feel like it’s so far off. Certainly it looks that way right now, [but] I feel like at any time things could start clicking."

Bumgarner's fastball topped out at 91 mph against the A's, not quite at the level he was at a couple of years ago, but still enough to be effective.

What was lacking this time around was the command of his pitches, which sometimes caught too much of the plate.

Catcher Stephen Vogt, who caught Bumgarner last year as well as Monday and was his teammate with the Giants before that, still believes the Bumgarner of old will resurface.

"Yeah, obviously he’s one of the best pitchers of our generation," Vogt said. "To me, it’s not him. I do know him and I know he’s a hard worker and I know he’s going to figure this out. He’s too good and he’s been doing it too long and, frankly, he’s too stubborn. There were some good things to take away from tonight. Just overall with Madison, his command needs to get a little bit better."

Until that happens, Bumgarner will keep searching.