De La Cruz hit a 455-foot home run at Washington on Wednesday night and then pointed to a plastic sensor covering on the end of his bat, a reference to umpires forcing him to remove it earlier in the game.
"Just to tell everybody that the knob is not the reason why I am doing a good job," De La Cruz said of the meaning behind the gesture. "It's because of all the work I'm putting out there."
De La Cruz went on to add two doubles and a run scored after the home run as the Reds won the game 9-2 to make it three in a row against the Nationals.
De La Cruz, one of the majors' top rookies and a key engine behind Cincinnati's rise to the top of its division, had an empty sensor cover on the knob of his bat. But it was removed after Nationals manager Dave Martinez questioned its use before De La Cruz batted in the second.
Umpires reviewed the legality of the knob cover with the league office and informed De La Cruz he was allowed to put it back on his bat for his second at-bat in the third.
"It's something that we use in spring training," De La Cruz said through an interpreter. "It's just a sensor that we use, but it's just the plastic that covers the bat. There's nothing else besides that. I started using it back in 2021. It just felt more comfortable using that, and from there on out I asked for more of those plastic shells."
After the game, crew chief Adrian Johnson said Martinez pointed out the knob cover to the umpires. Johnson said they checked with the league office, but it took a while to get a response.
"We had to continue to play, to keep the game going," he said. "They finally got back to us before his next at-bat and said that the attachment was approved. So, he played the rest of the game with the attachment on the bat."
After flying out to left in the third, De La Cruz opened the fifth with a deep drive to right-center against Josiah Gray. He then pointed at the end of his bat before rounding the bases.
Martinez was critical of De La Cruz's gesture.
"I am not trying to penalize this kid. I'm not. I love the way he plays the game," Martinez said. "I didn't like his antics after he hit the home run. We can do without that. He's only got two weeks in the big leagues, but he's going to be a good player."
It was De La Cruz's fourth homer since he made his big league debut June 6. He is batting .318 (35-for-110) with 14 RBIs and 11 steals in 26 games.
The Associated Press contributed to this report.