OAKLAND -- Jesús Aguilar took a moment to gather himself after fouling a pitch for the seventh time in what became an arduous eighth-inning at-bat against Guardians reliever Tim Herrin. Using the collar of his white Athletics jersey, he wiped beads of sweat off his forehead as he caught his breath.

These are the moments for which the A’s signed Aguilar as a free agent this offseason. For an offense that struggled mightily in 2023, the 32-year-old slugger brings the ability to change a game with one swing of the bat, and that’s exactly what happened in an eventual 6-4 loss to the Guardians on Wednesday.

On the 12th pitch of the at-bat, Aguilar got a slider slightly higher in the zone than the one he fouled off one pitch prior. This time, he fully connected, tagging the ball 100.3 mph off the bat and sending it into the Coliseum’s left-field bleachers for a game-tying three-run blast.

Aguilar admired the ball as it took flight for a few seconds before thrusting his arms down in elation. The moment certainly qualified as a celebratory occasion. Per MLB.com’s Sarah Langs, the 12 pitches in the dramatic battle were the most in a plate appearance that resulted in a game-tying or go-ahead homer in the eighth inning or later across MLB since … Aguilar himself! He hit a 13-pitch walk-off homer against the Marlins on April 21, 2018, while playing for the Brewers.

“It’s one of the better at-bats I’ve seen in a long time,” said A’s manager Mark Kotsay. “That’s incredible. You could just tell he was getting more locked in on each pitch. Got us back in the game on one swing. It was a great at-bat.”

Despite the rare feat, Oakland’s attempt at a late-inning comeback for a second consecutive day was thwarted.

As one of the few veterans on a young, rebuilding ballclub, Aguilar has made an effort to step up as a leader. Wednesday’s loss provided an opportunity for him to impart the importance of focusing on the team as a whole rather than individual performance.

“It doesn’t matter,” Aguilar said of his first home run with the A’s. “We didn’t win, so I don’t care. It was good, but it wasn’t enough. It’s not about me. It’s about winning games as a team, which, hopefully, we can start to do. It’s not about one player. It’s teamwork. If we want to start winning more games, we have to play as a collective team and start to do better things.”

There were some positives to take away after the A’s finished their first homestand of the season with a record of 2-4.

Rookie starter Kyle Muller has looked every bit of the pitcher the A’s hoped they were getting when acquiring him as part of the Sean Murphy trade this offseason. Building off a solid outing in Oakland’s Opening Day win over the Angels last week, the left-hander held Cleveland scoreless through the first five innings on Wednesday, with his only two runs allowed scoring after he departed with two outs and two runners on in the sixth inning on Cam Gallagher’s two-run double off Domingo Acevedo.

There’s also Ryan Noda, who capped a memorable first week in the Majors by crushing his first big league homer, a solo shot off Guardians reliever Nick Sandlin to begin the bottom of the eighth.

Still, even as the A’s played a playoff team in the Guardians tough over a three-game series -- two of the games went into extra innings while the other ended in a walk-off victory -- signs of their inexperience remain. Defensively, they committed an error in each of their first six games, which matches the longest season-opening streak by an A’s team in Oakland history since a 10-game streak to start the 1976 season.

As Oakland embarks on its first road trip of the season, first stopping in St. Petersburg for a three-game set with the Rays before heading to Baltimore for four more games, cleaning up the fundamentals will be a point of emphasis.

“We’ve played a lot of really close, tough games,” Muller said. “For a bunch of new guys that haven’t really gotten the chance to play together, I think once we sharpen up some things, we’ll get on a pretty good roll.”