The 20-year-old Dragovic of Belgrade, Serbia, went to the apartment he shared with the woman and found his belongings had been dumped out front, police officer April Harding said.
"He and the ex-girlfriend began to argue. He got mad and pushed her down," Harding said.
Dragovic was taken into custody and booked on suspicion of misdemeanor battery. Bail was set at $20,000.
The arrest caused him to miss No. 4 UCLA's 76-42 exhibition victory over Biola.
Bruins coach Ben Howland said he needed to gather all the facts before deciding whether to discipline Dragovic.
"She's a great kid. Nikola's a great kid. I'm very confident everything will be rectified soon," Howland said.