OAKLAND -- It took just eight words for manager Dusty Baker to sum up what went wrong as the Astros dropped a 5-3 game -- and thus the series -- to the A's at the Coliseum on Tuesday night.

"We outhit them," he said, "and then they outwalked us."

There is no simpler way to put it, as the Astros strung together seven knocks and three walks (two intentional) on the night, but were left searching for a big, timely hit right up until Oakland's Lou Trivino shut the door in the top of the ninth.

Houston pitchers were slightly stingier, allowing six hits to the A's -- but as Baker said, it was the walks that came back to bite them in the end.

Starter Luis Garcia entered the game on a career-high-tying five-game winning streak, hoping to continue his run and get the Astros back in the win column after dropping Monday's series opener. Making his fourth career start against Oakland, the right-hander issued a leadoff walk to begin his night but retired the next seven batters in order, striking out five in the first two innings.

But once the third inning rolled around, the A's began seeing Garcia better. Second baseman Jonah Bride started things off by legging out an infield single for the A's first hit of the day with one out. Garcia responded by inducing a quick groundout, but then walked the next two batters on eight pitches. That set the table for utilityman Chad Pinder, who crushed a 1-2 slider deep to left field for a grand slam -- all the offense Oakland would need on the evening.

Though Garcia struggled with his command all evening, he said that pitch to Pinder wasn't a mistake -- instead acknowledging that it was a good piece of hitting.

"I executed well. He hit it," Garcia said. "I can't do anything more than that, maybe throw it more outside."

Garcia's walks have been slightly down this season, so the back-to-back free passes that loaded the bases stung the most. Altogether, Garcia issued a career-high four free passes on Tuesday night, something that clearly irked him, speaking with an air of quiet frustration when he said, "I threw four walks. I don't like that. That's it."

Given Garcia's playoff performances in 2020 and '21, it can sometimes be difficult to remember that the 25-year-old is in just his second full season in the big leagues, having accrued a little over a year of service time. Entering Tuesday night, Garcia had 261 1/3 career innings in the Majors under his belt -- roughly one season's worth of innings for the workhorse pitchers of yesteryear.

"He's still learning. He's so young," Baker said. "On one hand, he showed more endurance with his pitch count. We've been trying to take him to that threshold. But like I said earlier, his command wasn't good, especially on his breaking ball."

While the new career high in walks will likely stick in his mind most of all, Garcia reached a more favorable career best on Tuesday night, tossing 108 pitches for the first time in the Majors. He grinded through 5 2/3 innings without his best stuff, which was a positive takeaway from an otherwise disappointing outing.

The deepest Garcia has been able to pitch in a game is seven innings, something he's accomplished four times in his career and twice in 2022 --most recently in a 6-0 loss to the Royals on June 4.

Though he's made 18 starts in 2022 (a figure in line with most qualified starters) -- his total pitch count for the season (1,568) ranks 56th out of 63 qualified starters, as do his total innings pitched (99 1/3).

Houston carries one fewer reliever than most clubs, as the team employs a six-man rotation, so any extra length from the rotation is always appreciated. If Garcia can continue the progression he's on and begin to pitch deeper into games, that would be extremely valuable as the club begins the push for its fourth World Series appearance in six years.

The Astros like what Garcia has given them so far, but the team is ready for him to take it to the next level. That starts with moving on from Tuesday's frustrating start.

"Luis can pitch, he can really pitch," Baker said. "We just don't want his confidence to get down. You've got to flush it and forget about this one, and go on to the next one."