HOUSTON -- This isn’t how the A’s were hoping their longest road trip of the year would start out.

After they put together a sterling opening homestand to begin their non-Japan portion of the regular season, the good times, at least for the time being, have stopped rolling, by way of a 9-8 loss to the Astros in a wild one Sunday at Minute Maid Park.

“I think the majority of the game, there was frustration,” manager Bob Melvin said. “It is what it is. They ended up winning the game.”

Oakland's day ended when Blake Treinen issued a tie-breaking four-pitch bases-loaded walk to Houston sparkplug José Altuve in the ninth. That marked the end of Treinen’s scoreless streak, which had reached 24 2/3 innings, dating back to Aug. 25 of last season.

There appeared to be some dissension from Oakland’s dugout regarding the calls made behind the plate several times in the late innings, but A’s players declined to comment on the umpiring after the game.

“We have to be careful how we comment on things because it’s not really acceptable to truly speak your mind at times,” Treinen said. “But back to it, I have to make better pitches to Altuve. We still had a chance to get out of that inning. I didn’t give any competitive pitches there late.”

Treinen was called upon in the eighth inning, tasked with the challenge of a five-out save, but the A’s 8-7 lead evaporated under his watch when Alex Bregman’s sacrifice fly tied the game.

That play was as much of a turning point as anything that happened in the ninth. Bregman’s fly ball wasn’t hit particularly hard, and it didn’t travel particularly deep. But it was just enough to score George Springer, ahead of an on-point throw by center fielder Ramon Laureano

“Weak contact’s what you’re looking for, and it didn’t work out, because Springer’s fast and he just beat the ball to the plate,” Treinen said. “They had a lot of things go their way because they do a lot of things successfully at the plate. They put pressure on you at all times. Today it fell in their favor and we just didn’t catch a break late.”

Treinen downplayed the question of whether his ninth-inning struggles may be a byproduct of the disappointing results of the weekend sweep by the Astros.

“We’re professionals,” he said. “There’s certain variables you can’t control and there’s some things you can. Those are the ones you try to focus on. Me delivering a pitch in the zone is something I can control, or not control, against Altuve.

“If I do a better job of being in the zone there instead of yard-selling the first two [pitches] ... I didn’t give myself much of a chance to be successful in that at-bat. It’s frustrating when our team played as well as they did to stay in it.”

Phegley: “The tension’s always there.”

While technically true, the well-worn baseball cliché “You can’t win divisions in April” leaves room for interpretation. Catcher Josh Phegley categorized this early-April series with Houston as having a “late-September feel to it,” and fully admitted the A’s are “champing at the bit to get these guys.”

“They’ve had some success,” Phegley said. “We want that success. This is maybe a little added pressure. This is going to be a battle all year long. That’s the divisional battle. And that’s how tough this division is.”

Wendelken comes through

The A’s are in their longest stretch of consecutive games -- 18 -- without a day off, and their bullpen entered Sunday’s game leading all of baseball with 44 1/3 innings pitched.

That’s a combination that screamed for the need for longevity from the starting pitcher, but Mike Fiers was out of the game after 1 2/3 ugly innings.

The A’s needed a stopper, and they got one in the form of reliever J.B. Wendelken, who stepped in for 3 1/3 shutout frames.

Wendelken entered the game with the bases loaded and two outs in the second and struck out Max Stassi, and he allowed just one hit over the next three frames, striking out three.

“He was basically the key to the game,” Melvin said. “The guy that kept us in it. For a guy that’s a one or two-inning reliever to give us what he did, it was phenomenal. He was literally the guy that gave us the chance to come back.”

The 26-year-old Wendelken, who made his first Opening Day roster this year and has limited Major League experience across three seasons, diffused a mess after Fiers yielded six runs while recording a total of five outs.

“When things don’t go our way we have to adjust to that period,” Wendelken said. “Me having to come in that early and fight off that good offense for that long, it’s really good for the team.”