Two brothers who bashed a high-ranking Victorian police officer may face up to 15 years behind bars, after their bid to keep their case in a lower court failed.

Jay Stephens, 20, and Isaiah Stephens, 19, have admitted to recklessly causing serious injury to Assistant Commissioner Chris O'Neill on the grounds of St Kevin's College at Toorak on June 15.

Isaiah Stephens leaves court on Wednesday. Credit:AAP

More serious charges of intentionally causing serious injury were dropped by prosecutors as part of the plea deal.

In Melbourne Magistrates Court on Wednesday, the duo's lawyers applied for summary jurisdiction, which would mean their case would remain in the Magistrates Court, where the maximum penalty for the crime is two years in jail.