HOUSTON -- Ken Waldichuk couldn’t make it out of the third inning on Sunday at Minute Maid Park, and the A’s ended a six-game road trip through Texas on a less-than-ideal note.

Waldichuk, the A's top pitching prospect per MLB Pipeline, cruised through the first two innings but struggled in the third, and it only got worse from there for Oakland in an 11-2 loss to Houston.

Waldichuk surrendered five runs on five hits with three strikeouts in 2 2/3 innings, the shortest outing of his young career. It was the second straight outing in which Waldichuk allowed five runs, after he yielded just four runs combined over 10 innings in his first two starts.

The left-hander said Houston’s lineup was a good challenge, but it was also a learning experience.

“Command was better than the previous starts, I thought,” Waldichuk said. “They had some good approaches, hit some pitches and capitalized on those baserunners.”

After striking out Chas McCormick to start the third, Waldichuk allowed five straight baserunners, underscored by a three-run double by Yordan Alvarez and an RBI double by Alex Bregman. Waldichuk induced a flyout from Kyle Tucker, but Yuli Gurriel’s RBI single ended his day.

A's manager Mark Kotsay said Waldichuk’s command was particularly good in the second inning.

“Third inning, he came out and lost command of that fastball arm side,” Kotsay said. “He tried to get in the lane down and away, he couldn’t locate it, and then he was forced to use the breaking ball up in the zone, and they really took advantage of that.

“Again, we talk about this lineup and this team. We’ve played some really good teams. Obviously, [the Astros] -- middle of that order is exceptional, and you’re not going to get away with mistakes.”

The A’s were able to get some offense going in the sixth but missed the chance to get to Astros starter Framber Valdez, who set an MLB single-season record with his 25th consecutive quality start. 

Dermis Garcia hit a two-run double in the sixth, accounting for both of Oakland’s runs. It was his second two-run knock of the series after lacing a two-run single in Thursday’s series opener.

“I think Dermis is continuing to show us his ability to hit the baseball and drive the baseball,” Kotsay said. “The ball he hit today had some top spin but got over the left fielder’s head. It was hit well. He’s continuing to take good at-bats.”

Sean Murphy followed Garcia with a hard-hit ball down the third-base line, but Bregman made a diving stop for the out. Two more grounders to third ended the sixth.

“A lot of young hitters in this lineup that are making adjustments. The league is making adjustments to them, and when you’re facing a quality team with quality pitching, they have the opportunity to really exploit some holes,” Kotsay said. “I think we saw that this series. That’s part of the process, as well.”

It was a special day for Jordan Diaz, who got his first Major League hit in the seventh on a single to center off Phil Maton.

“It was truly special for me, because it’s been a dream come true,” Diaz said through an interpreter. “I’ve dreamed of this for a very long time. … When I went out there for the first inning, when it was my turn to go, I just felt overwhelmed. It was such an exciting feeling. I just felt very proud, and I’m just very happy to be here.”

Diaz, Oakland’s No. 8 prospect, was recalled from Triple-A Las Vegas on Sunday after Ramón Laureano went on the 10-day injured list with a right hamstring strain.

“Diaz, obviously, getting that first one out of the way is big,” Kotsay said. “He did it really nicely on a fastball in, stayed inside the baseball. We’ve been hearing what kind of hitter he’s been this year, and that was an at-bat that really reflects it.”

With 15 games remaining, Oakland has nine games left against playoff teams and contenders, including the next six at home against the Mariners and Mets.

“I think this team has competed all year,” Kotsay said. “We fight. We have shown that. We’re playing some good baseball teams right now that are going to be in the postseason, that you are going to watch play in October. ... It’s a test, and we are going to continue to grind.”