Rihanna, Chris Brown

Rihanna has been subpoenaed to testify at a June 22 preliminary hearing in the assault case against Chris Brown, her attorney told TVGuide.com.

"In a pre-arrangement at my office, she was subpoenaed Tuesday afternoon," Donald Etra said. "She is legally required to appear at the June 22 hearing. She will testify if called by the District Attorney or defense counsel."

The appearance will be Rihanna's first in court since Brown was charged with two felonies — assault and making criminal threats — following his February arrest after an incident between the two. He has pleaded not guilty.

The hearing will determine if there's enough evidence for the case to go to trial. If a plea deal is struck prior to the date, the hearing and case could be dismissed, Etra said.

Brown has already lost a bid to delay the June 22 hearing. His attorney, Mark Geragos, had argued that the hearing should wait for a related California Supreme Court decision. Geragos said in his appeal that a case currently under consideration could affect Brown's access to police records that Geragos said were crucial to the hearing. The appeal was rejected Wednesday, but the order did not specify why, Patricia Kelly, a spokeswoman for the Los Angeles Superior Court, told TVGuide.com.

TVGuide.com's calls to Geragos were not immediately returned.