The denial is the equivalent of a not-guilty plea in juvenile court. The fourth teen will be arraigned April 15.
The defendants are among a gang of six teenage boys and a 19-year-old man, identified as Michael Sykes, accused of attacking the girl on March 10 in the restroom of Victoriano Park. The charges against each teen include rape, sodomy and committing the crimes to benefit a criminal gang.
The juvenile court judge on Monday asked for a probation report on four of the juveniles to help determine if they should be tried as adults. Riverside County Judge Robert J. McIntyre said he wants the reports by April 25 as he considers the case against the defendants, whose ages range from 15 to 17.
Police say the victim was lured to the park by an older girl with ties to the gang. Deputy District Attorney Lisa Loyola said the alleged group rape was horrific as presented to prosecutors.
"This was a lot of boys in a bathroom with an 11-year-old girl," Loyola said. "She didn't know any of them at all. She was new to the area ... and didn't know the culture of the area or what to look out for."
Sykes was charged with six felonies, including kidnapping for rape, four counts of aggravated sexual assault on a child and committing a crime to benefit a criminal street gang. He also faces several sex offense and kidnapping enhancements.
His arraignment is set for April 13.
The Associated Press contributed to this report.