Arron Warren, 30, of North Boarhunt, was allegedly struck over the head by a Devon and Cornwall officer near Fratton Park after the Plymouth Argyle v Pompey match on May 12, 2016.
A police watchdog has recommended a disciplinary hearing following the CPS refusing to prosecute.
‘The officer in question remains on full active duty whilst this process takes place,’ a spokesman for Devon and Cornwall police said. The date for the hearing is yet to be set.