The Chicago Cubs have apologized for a song that was played after reliever Aroldis Chapman left the mound during Sunday's game.

The Cubs said an employee played Prodigy's "Smack My Bitch Up" after Chapman pitched the ninth inning of a 6-4 loss to the St. Louis Cardinals. That employee was fired Monday.

"We apologize for the irresponsible music selection during our game last night," Cubs president of baseball operations Crane Kenney said in a statement. "The selection of this track showed a lack of judgment and sensitivity to an important issue. We have terminated our relationship with the employee responsible for making the selection and will be implementing stronger controls to review and approve music before public broadcast during our games."

Chapman, who the Cubs acquired from the New York Yankees at the trade deadline, missed the first 29 games of this season under baseball's domestic violence policy. He was involved in an October incident where he allegedly choked his girlfriend.

Police did not file charges against the Cuban-born left-hander, citing insufficient evidence, conflicting stories and uncooperative witnesses. Major League Baseball announced Chapman's suspension in early March, two months after the Yankees traded four minor leaguers to the Cincinnati Reds for the All-Star closer.

Information from ESPN staff writer Jesse Rogers and The Associated Press contributed to this report.