The boy claims Yayo and several associates surrounded him and threatened him for wearing a Czar Entertainment shirt, a label/management firm run by Rosemond that represents a number of rappers, including G-Unit rival The Game.
The teen also claims Yayo and associates flashed handguns tucked into their waste.
Yayo's attorney Scott Leemon said he provided the District Attorney's office with an affidavit from a witness who knows both Yayo and Rosemond's son.
"He stated [in the affidavit] that he saw the entire thing and [that] Yayo was not the person who slapped the kid," Leemon revealed to AllHipHop.com.
The judge ordered the DA to investigate the credibility of the claims of the alleged witness in the affidavit.
A judge dismissed a motion by Leemon to subpoena emails sent between publicity firm 5W Public Relations and Rosemond, which the attorney sought for unknown reasons.
In March, Yayo was charged with assault, harassment, and endangering the welfare of a child.
In July, the 29-year-old rapper rejected an offer of nine months in prison, in exchange for pleading guilty to slapping the boy.
Yayo is currently free on $5,000 bond and is due back in court on October 30th.
A judge will decide if Yayo's case should be tried with another defendant in the case, Lawell Fletcher.