OAKLAND -- The A’s envision Jesús Luzardo developing into a pitcher who can anchor their rotation for years to come. The guy who can shut down opposing offenses on a consistent basis. The ace.

That evolution could take place in 2021, Luzardo’s second year in the big leagues as a starter. But as Friday’s 9-5 loss to the Astros showed, there are still some growing pains the 23-year-old lefty might have to endure before reaching that next level.

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Luzardo offered a glimpse of how dominant he can be with eight strikeouts in five innings against Houston. There were also signs of the issues that led to his up-and-down rookie campaign last season. The end result: Five runs allowed on eight hits with one walk.

“At times, he looked really good,” A’s manager Bob Melvin said. “They hit some mistakes. Looked like they hit some balls down the middle. He just has to get a little more consistent, control the damage and try to stay away from crooked numbers in big innings.”

Luzardo's electric fastball maxed out at 98.2 mph. While it was overpowering Astros hitters at times, that same fastball also resulted in a pair of homers -- a three-run homer by Alex Bregman in the third and solo shot by Yuli Gurriel in the fourth. Shortly after Gurriel’s homer, Michael Brantley also belted a fastball from Luzardo off the wall in left for an RBI double.

The common theme with those fastballs? They were all left up in the zone at 95 mph. It appeared as if the Astros were intent on ambushing that fastball, knowing how often Luzardo threw it. Of his 92 pitches, 48 were fastballs, and 15 were left high in the zone, including those three big hits by Bregman, Gurriel and Brantley

“First time around [the Astros’ batting order], fastball up worked really well,” Luzardo said. “Second time around, I started doing it, and I guess they were prepared for that. I felt like I made some good pitches, but they made some adjustments.”

There is a method to Luzardo’s fastball-driven approach. As baseball advances with analytics, certain trends often gain steam around the league. The latest pitching movement making its rounds is to throw four-seam fastballs higher in the zone as a counter to the increased focus on launch angle by hitters.

Though Luzardo is young, he entered the Major Leagues with more of an old-school approach. He’s never been huge on pitching metrics, like spin rate. During his ascent through the Minor Leagues, he didn’t throw this many four-seamers, relying more on his sinker down in the zone. The end result of the adaptation to more fastballs might pay off. For now, Luzardo has some work to do.

“I’m working on fastballs up, because baseball is moving in that direction,” Luzardo said. “Four-seamers up, spin rate, all of that stuff, I’ve never been big into that. I started working on it and felt like I found the top of the zone for the most part today. On the four-seams, I need to make some changes. That is something I’m working on.”

One positive takeaway for Luzardo was his final inning. He bounced back from the Astros’ breakthroughs in the third and fourth with his only 1-2-3 frame of the night in the fifth, requiring just 10 pitches to get through the middle of Houston’s order. In that inning, he threw curveballs for five of his 10 pitches, showing more of the mix of speeds he’ll look to display against the Dodgers his next time out on Wednesday.

“Going back out there and making it a quick inning to get us back in was big,” Luzardo said. “That being my last inning, getting a zero there was definitely big for me.”

One area the A’s did not anticipate much struggles from this season was their relief corps. The A’s bullpen shined last year as a key component of their run to capturing their first American League West title since 2013, combining to lead the Majors with a 2.72 ERA. Two games into the regular season, though, that bullpen has allowed early deficits to grow even larger.

On Friday, Jake Diekman, who is expected to fill the closer role on an interim basis with Trevor Rosenthal on the injured list, entered the ninth with the A’s only trailing by one run, but he departed after recording two outs and allowing the deficit to grow to three.

After being silenced by Zack Greinke on Opening Night, the A’s offense showed signs of life on Friday. Ramón Laureano, who exited the game in the seventh with a jammed left wrist, provided a spark with a booming RBI triple in the fourth. Chad Pinder, who entered the game in the seventh as a pinch-hitter, narrowed the deficit even further with a two-run shot off Astros reliever Brooks Raley.

“We’re gonna have to hit,” Melvin said. “When you play these guys, you have to score some runs. It was good that we got back in the game. We were one run away there for a little while, and it got away from us in the ninth. We swung the bat a little bit better tonight.”