LAFAYETTE — The last piece of Jonathan Lucroy’s full-body armor was built, like the others before it, before dawn.

It’s 6 a.m. Thursday, just days before Lucroy, the former Louisiana-Lafayette backstop, reports to Arizona for spring training with the Milwaukee Brewers. It’s the final day of a rigorous offseason training program fueled by a chip on Lucroy’s shoulder.

“I’m not saying I didn’t train hard last season, but I think there was an extra little push I had in there (this year),” Lucroy said. “You know what? I had a bad year last year. It’s almost like ‘I need to prove a point’ type of training.”

Alongside younger brother David, a pitcher in the Brewers organization, Lucroy strides into the sprawling Maximum Intensity Training room at Red Lerille’s Health and Racquet Club with quiet focus. For the next two hours, the Lucroy brothers’ bodies belong to friend and personal trainer Eugene Kwarteng.

“He’s like a strength training genius,” David Lucroy said.

That genius feels devious to the Lucroys on this morning. The amicable nature of their relationship with Kwarteng doesn’t lead to a friendly two hours, and that is by design.

This was an important offseason for the elder Lucroy. After a breakout 2014 in which he finished fourth on the National League MVP ballot with a .301 batting average and an MLB-record 46 doubles as a catcher, a broken toe and concussion robbed him of a large chunk of 2015.

When he was on the field, his performance didn’t meet his lofty expectations. In 103 games, he hit .264 with a .391 slugging percentage, both the lowest figures since his 2010 rookie season.

It was a disappointing individual season in the midst of a disappointing team season. The Brewers finished 68-94, tied with the Rockies for the fourth-worst record in baseball. But it gave Lucroy some perspective heading into the winter.

“The biggest mistake you can make as a professional baseball player — or any athlete in general — is taking things for granted,” Lucroy said. “You’ve always got to keep the mindset that whatever you do isn’t good enough. Whatever people do around you isn’t good enough. That helps you push them; it helps you push yourself to get better every year.

“You don’t ever want to be content with being who you are or what you are. You need to push yourself to the next level because, if you aren’t, someone else will be.”

So Lucroy pushed harder this winter, and Kwarteng was ready to help.

This was Lucroy’s fifth offseason working with Kwarteng, whom he met during his college years while Kwarteng was a member of the Cajuns football program. Both are adopted residents of Lafayette, and David Lucroy was along for the ride for the first time after going through his first year of professional baseball in 2015.

“It was a healthy competition,” Kwarteng said. “He’s a good big brother, really looking out for his younger brother and keeping him sharp, too. That was probably the best part of this offseason, them working out together.”

The group meets near a set of pull-up bars with TRX straps hanging from them like jellyfish tendrils, waiting to deliver a sting to whoever touches them. Few words are exchanged. David Lucroy and Kwarteng greet with a gladiatorial handshake — hands forcefully gripping the other’s forearm. Kwarteng looks at Lucroy and asks, “You good?” Lucroy responds with a nod.

It’s time to get to work.

The goal this year was to improve last season’s shortfalls. After a warmup, Lucroy sidles up next to Kwarteng and allows him to work on his neck. It almost looks like a cross between a massage and an assisted stretch; Kwarteng said it’s a preventative measure for concussions.

Lucroy also was looking to address his swing. It felt out of whack last season, disjointed, like his legs were moving at a different speed than his torso, which was moving at a different speed than his hands.

To fix that problem, the TRX straps — adjustable-length cables with handles at the end used for suspension training — took on a bigger emphasis in Lucroy’s training regimen this year. They allowed Kwarteng to isolate specific muscles while activating Lucroy’s midsection.

“He would initiate, and then some disconnect would happen to where he wasn’t able to generate as much power in his swing,” Kwarteng said. “We did a lot of work with single limbs ... and it really helped him tie his core together. That way, whenever he does hit or throw, it’ll be his whole body doing the work instead of just his arms or just his legs.”

They barely stopped during the entirety of their training session. Kwarteng’s training plan emphasized near-constant movement with limited time to rest, blending strength and cardiovascular training into one.

“It’s very painful, but it’s very good for you at the same time,” Lucroy said.

The Lucroys were finishing up their 14th week with Kwarteng. The first six weeks were strictly to build strength, and the last eight were geared toward performance. Each Sunday, he would send the brothers a plan for the week, usually consisting of two upper-body days and two lower-body days.

This is one of the days the Lucroys focus on upper-body training. The brothers trade off alternating workouts in a superset — one set of one exercise, followed immediately by a set of another exercise — before taking an almost nonexistent breather. Then it’s on to the next set of exercises.

For nearly two hours, they pushed and pulled, much of the resistance provided by their own body weight, their cores forced to stabilize while their legs were suspended in the TRX straps. They hurled medicine balls against the wall. They slapped heavy ropes against the green turf. They chopped their feet while navigating a rope ladder on the ground. They zigzagged sprints between cones spaced 10 or 15 yards apart. They were gassed.

Their exhaustion had a purpose, though. For David, it was indoctrination to what it took to train at a big-league level. For Jonathan, it was adding layers of armor to what was already a strong foundation.

“This is one of the better offseasons he’s had — pretty close to the one he had before the breakout year,” Kwarteng said. “That one and this one are, based on his body language and how strong he’s gotten, it’s like, ‘Oh yeah, he’s got that charge. He’s ready.’ ”

Nothing was left to chance or taken for granted; the chip on Lucroy’s shoulder from 2015 wouldn’t let that happen.

He has put in the work. Now it’s time to bounce back.

“The punishment and pain of the season, the rigors of the season, that kind of stuff protects you from it,” he said. “That’s the way it is; that’s why we do these kind of workouts.

“It’s like full-body armor. It helps you to be protected. As Eugene says, ‘This is your full body armor; it’s what creates your armor.’ And it’s true.”