LAS VEGAS -- Darell Hernaiz showed up to the A’s Spring Training complex a week before even pitchers and catchers reported and felt confident that the strides he made in the Minors throughout 2023 were sufficient to reach the next level.

Then came a reality check.

While making his way to the practice fields in Mesa, Ariz., Hernaiz was met by A’s infield coach Eric Martins, who escorted him to the video room inside the complex. Martins pulled up a playlist of Hernaiz’s defensive plays from the past season at Double-A Midland and Triple-A Las Vegas. But this was no highlight video.

“I wanted to stump him a little bit,” Martins said. “He improved towards the end of last year, but it still wasn’t what we needed to see for him to come out and play either short or third in the big leagues. … There were double plays I showed him that need to be turned in the big leagues, but because of waiting back on balls and getting the second baseman a feed late, the guy was safe at first.”

Hernaiz was caught off guard. Here he was thinking Martins was going to praise him for his improvements last year. Instead, it was a dissection of the flaws that needed to be corrected.

“I wasn’t expecting it,” Hernaiz said before Saturday’s split-squad game against the Brewers at Las Vegas Ballpark. “But it helped me out. I came in already motivated, then he gave me some things I was doing wrong and needed to work on.”

Fast forward about a month later, and Hernaiz, ranked Oakland’s No. 5 prospect by MLB Pipeline, finds himself a regular in the A’s starting lineup for Cactus League games. Entering Saturday, he logged seven starts at shortstop, his natural position, and three starts at third base, a position that remains up for grabs this spring.

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Given how well Hernaiz has performed at the hot corner to this point, he just might be the right man for the job.

“The improvement that he’s made in the last month shows you that it’s in there for him,” Martins said. “He’s put away those defensive concerns. Now you see the progression of him getting better and knowing that every day he’s going to have to work. All the guys we had in the past, [Matt] Chapman, [Marcus] Semien, [Matt] Olson, those guys continue to work every single day, and those are Gold and Platinum Glove winners.”

The main issues surrounding Hernaiz’s defense centered around his arm strength and footwork. Those mechanics have since been cleaned up through daily infield work.

“He’s got the arm strength, he just didn’t know how to use his arm,” Martins said. “It all starts with the feet. Once he started dialing in and using his feet the right way, now you see the arm strength that’s in there. He’s really improved since Day 1 of camp. Every day, he comes out and wants more. He’s put in the work, and he’s opened a lot of eyes because of that.”

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Beyond his .227 batting average in nine Cactus League games, the A’s have been impressed with the quality of Hernaiz’s at-bats. Plus, he performed as arguably the organization’s top hitter in the Minors last season, combining for a slash line of .321/.386/.456 with nine home runs, 32 doubles, 71 RBIs and 13 stolen bases in 131 games between Double-A and Triple-A.

With third base likely his best shot to make the A’s Opening Day roster -- Nick Allen is expected to enter the season as Oakland’s starting shortstop -- the final question surrounding Hernaiz and his big league readiness comes down to defense. Can he handle playing third base regularly in the Majors?

“I think he can,” Martins said. “That was something I wanted to see. Now that he’s able to move his feet the right way, it’s becoming a little easier for him. … From what we’ve seen in the innings that he’s played at third, I think he’s capable of going out there and being a pretty good defender.”

Should Hernaiz man third for Opening Day on March 28, at 22 years and 238 days old, he would become the second-youngest third baseman to start for the A’s on Opening Day since the club moved to Oakland in 1968. Eric Chavez (21 years old in 1999, and 22 years and 118 days in 2000) is the youngest.

“I do feel like I’m showing in my at-bats, defense and how I take care of my body, that I have what it takes to be a big leaguer,” Hernaiz said. “We’ll see what happens, but I definitely feel like I’m ready.”