WASHINGTON — Cincinnati Reds rookie Elly De La Cruz pointed at the knob of his bat after hitting a 455-foot homer at Washington on Wednesday night in a reference to the removal of a covering earlier in the game.

Before De La Cruz led off the second inning, umpires had the slugger remove a white or clear object from the end of his bat. It looked as if it was an empty covering designed to hold a sensor that takes measurements at the plate.

Nationals manager Dave Martinez talked to plate umpire Quinn Wolcott about the knob piece before it was removed. Reds manager David Bell came out to discuss the situation with the umpiring crew.

De La Cruz then struck out swinging.

After umpires reviewed the legality of the knob piece with New York, the infielder was allowed to put it back on before his second at-bat in the third. Major League Baseball said “the housing” is permissible, and that was communicated to the Nationals.

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. He added a double and a run scored in the top of the eighth inning.

It was his fourth homer since he made his big league debut June 6.