ATLANTA  --  When the Braves released their lineup for Wednesday night’s game against the Red Sox, there were two quick responses.  

1. Why is Ronald Acuña Jr. not playing, and is he hurt? 

2. Why is Orlando Arcia the designated hitter, instead of William Contreras or Marcell Ozuna? 

Well, Acuña is dealing with a sore groin that may need just a day or two of rest. As for Arcia, he might need just a day or two to come down from the high he experienced when he capped a three-hit game with a game-ending homer that gave the Braves a 5-3 win over the Red Sox at Truist Park.

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“I didn’t know if it was going to go or not,” Arcia said through an interpreter. “I’m just happy I was able to get it out and get the team the victory. That’s all we’re looking for.”

Arcia’s first career game-ending homer gave the Braves their first walk-off win of the season. The reigning World Series champions haven’t experienced any extended stretches of success yet. But there is hope this energizing shot from an unexpected source might serve as a much-welcomed spark.

“You never know when you’re going to look back on a game or a big win and know that is the one that got you going,” Braves manager Brian Snitker said.

Or in Arcia’s case, you never know when you’re going to come to the park and learn that you’re finally in the lineup. He arrived Wednesday afternoon not knowing he would be playing. He had totaled just one plate appearance over a 14-game stretch that dated all the way back to April 26.

But Arcia singled ahead of Travis Demeritte’s two-run homer in the Braves’ three-run third. He still looked quite comfortable when he ended the game by crushing Ryan Brasier’s center-cut 2-0 fastball. His home run cleared the 385-foot sign in left field and set the stage for him to be showered with water by his celebratory teammates as he crossed the plate.

“I’m going to sleep like a baby tonight,” Arcia said when asked how he felt after experiencing this thrill.

If the Braves are going to get rolling, or at least win as many as three straight games for the first time this year, they are going to need a healthy Acuña. The 24-year-old outfielder tweaked his right groin in Tuesday night’s 9-4 loss to the Red Sox. The club decided to sit him on Wednesday with the hope he’ll be ready after resting again on Thursday’s off-day.

The good news is that Acuña hasn’t experienced any right knee issues during any of the 10 games he has played since returning on April 28 from a torn right ACL. His presence in the lineup makes a significant difference both offensively and defensively.

With Acuña out, the Braves chose to place Ozuna in left field and Demeritte in right. Demeritte’s inconsistent jumps and Ozuna’s subpar arm leave Atlanta with a weak outfield mix.

Arcia played five games in left field during April. But it didn’t take long to see that the shortstop was not ready to play the outfield. He was credited with -4 outs above average as an outfielder, per Statcast. As for getting playing time as a middle infielder, Dansby Swanson and Ozzie Albies have played every game this season.

So when Snitker constructed his latest lineup without Acuña, he placed Arcia in the DH role. Contreras, the backup catcher, seemed like the better option. But by the end of the night, the veteran skipper had silenced those who questioned this lineup decision.

“He hadn’t been playing a lot,” Snitker said. “He started off the year getting some at-bats. He hasn’t lost his enthusiasm, the energy and everything. He’s a good player. He got a hit off the closer for the Mets [Edwin Diaz] the other day. So I’m happy for him.”

Arcia enjoyed a three-hit game at Dodger Stadium on April 19, and he is tied with Prince Fielder for the most home runs (four) in Brewers postseason history. The 27-year-old has tasted success in the past and provided value this year, while never knowing when he might get his chance to play.

“Whether I’m playing or not playing, I’m coming to the ballpark with that same energy,” Arcia said. “If I’m in the lineup, I’m going to put 100 percent of my energy into being in the lineup. If I’m not, I’m going to put 100 percent of my effort into supporting my team.”