"I was battling throughout the whole game," Gallardo said. "The command just wasn't there."
Gray took a no-hit bid into the eighth inning, whereas Gallardo was gone in the fifth. Gallardo, making his sixth straight Opening Day start, allowed four runs on six hits -- four that went for extra bases -- and one costly walk. He is now 1-3 with a 5.12 ERA on Opening Day, including the five with the Brewers.
"There is always extra excitement and energy going through you because you know it's the first game," he said. "You've got to find a way to control it. Obviously, things didn't go the way I wanted, but you have to forget about it and get ready for the next one."
Gallardo started his night by striking out Craig Gentry. But then Sam Fuld hit a 2-1 fastball to deep center field, where outfielder Leonys Martin just missed making a great catch against the wall.
The ball eluded Martin, and Fuld raced to third for a triple. Ben Zobrist followed with a two-run home run to give the Athletics a two-run lead.
"I was just falling behind hitters, and you can't do that," Gallardo said. "You've got to be aggressive and throw strikes. When I did get ahead, I was able to get them to swing at my pitch and get ground balls."
Gallardo was also able to put up two scoreless innings after that before starting the fourth by walking Ike Davis. That cost him, as the Athletics scored two more runs. After Brett Lawrie flied out, Stephen Vogt smacked a double to left to put runners on second and third. Marcus Semien's single to center scored one run and Gallardo sent home a second run on a wild pitch.
"He only made a couple of mistakes in the first," manager Jeff Banister said. "He got chipped a little bit, but these hitters make you work and stay patient. You have to get ahead of them, get the hitters in a swing mode and get early outs. We were not as efficient as we would like."
Gallardo's night ended at 89 pitches when he gave up a single to Zobrist to start the fifth. His next start will be his first in Arlington, on Saturday, when he goes against the Astros.
T.R. Sullivan is a reporter for MLB.com. Read his blog, Postcards from Elysian Fields, and follow him on Twitter @Sullivan_Ranger. This story was not subject to the approval of Major League Baseball or its clubs.