OAKLAND -- Brent Rooker finished his first month in an A’s uniform by turning in a performance befitting of the tear he’s been on.

A scorching April for Rooker concluded with a two-hit effort highlighted by launching his ninth home run of the season -- a towering 411-foot solo blast to lead off the bottom of the fourth inning that sailed into the second deck of the Coliseum -- in Sunday’s 5-4 walk-off win over the Reds punctuated by a clutch single from Esteury Ruiz.

Rooker’s nine homers this month are the most by an A’s player in April since Khris Davis hit 10 in 2017. Mark McGwire set the franchise record with 11 in 1997.

“Eye-opening,” manager Mark Kotsay said when asked to describe Rooker’s month. “In terms of just the quality of the at-bats and the impact that he’s had in the middle of the order, stepping in and really producing for us has been huge. I think he’s always believed in himself. He’s a confident kid, and he’s taken every opportunity we’ve given him and really run with it right now.”

Rooker hit .358 with nine homers and a 1.262 OPS in April. He was already leading MLB (min. 50 PA) with 230 wRC+ in the month, via FanGraphs, before Sunday's 2-for-2 day at the plate. His nine homers, meanwhile, are second in the American League behind only Rafael Devers, who has 10.

“It’s fun to watch,” said A’s starting pitcher Ken Waldichuk, who allowed three runs on six hits and a walk with a season-high seven strikeouts over 5 2/3 innings. “Every time he comes up, it seems like he’s executing. Even if he’s not executing, the ball is still leaving the park. It’s been awesome to see all his hard work pay off.”

When it comes to candidates for April’s American League Player of the Month, Rooker certainly deserves to be in the discussion. Should he win it, the outfielder/designated hitter would become the first A’s player to receive the honor since Josh Donaldson earned it in September 2013.

Making Rooker’s numbers all the more impressive is the fact that he began the season going 0-for-7 and did not register his first hit until April 8. Since then, however, few hitters in baseball have swung it as well.

Over his last 19 games, Rooker is 24-for-61 (.393) with nine homers, two doubles and 22 RBIs, having also drawn 14 walks. In that time, he’s struck out just 14 times in 79 plate appearances.

“In a vacuum, the numbers themselves are more than I ever thought I could do,” Rooker said. “That’s not taking away the confidence I have in myself. That kind of production for a month’s worth of games is probably past even my expectations of myself, so that’s been a pleasant surprise for me. 

“The most productive part of this first month is that I’ve learned a lot from every at-bat that I’ve had," Rooker added. "I think that’s going to help me just continue to get better and grow as a player.”

Prior to 2023, the most playing time Rooker ever received over a Major League season came in ‘21, when he played in 58 games and amassed 213 plate appearances as a budding top prospect with the Twins. Back then, Rooker recalled weeks of success that were followed by weeks of struggles.

Asked what has changed from then to now, Rooker said there haven’t been too many adjustments from a mechanical standpoint. It all comes down to experience.

“I think it was just the mental determination to just not stop getting better,” Rooker said. “The last two years, I’ve just been trying to figure out how to extend those good times that I had. I knew I could do it because I’d have weeks in Minnesota where I’d hit really well with a lot of success. That put it in my head and heart that I was good enough to do it. I just had to figure out how to do it for longer periods of time.”

In what was a miserable month for the A’s that saw them set an MLB record for most losses (23) before the end of April, Sunday afforded them a chance to finish on a high note as they flip the calendar to May.

“I think this has been one of our more challenging months, personally,” Kotsay said. “Today was needed for the confidence. You could see it in the celebration. It was good to hear the music in the locker room with the free-throw shooting they do after the game. They needed this win today.”