DALLAS (Reuters) - A Dallas County grand jury has indicted former NFL quarterback Johnny Manziel on a charge of misdemeanor assault with bodily injury after he allegedly struck his ex-girlfriend, media reported.

A grand jury examined in the case against Manziel last week and a decision on an indictment was expected on Monday. If tried and convicted, he could face up to a year in jail.

KRLD radio, a CBS affiliate, reported late on Sunday that Manziel, 23, had been indicted on a class A misdemeanor domestic violence assault charge, citing a Dallas County District Attorney's office source. Other media also reported the indictment.

Neither the Dallas County district attorney's office, nor Manziel or his attorney, could immediately be reached for comment.

However, Manziel's attorney told a CBS affiliate on Sunday that he expected an indictment, the station reported.

The charge against the former Heisman Trophy winner stems from an incident in which Manziel is accused of hitting, kidnapping and threatening to kill Colleen Crowley, 23. Crowley accused Manziel of hitting her so hard that she temporarily lost her hearing, court papers show.

Crowley told police she was assaulted at a Dallas hotel and then again while driving to her home in Fort Worth, according to a police report.

The case was referred to the grand jury, which hears evidence behind closed doors.

Manziel, known as "Johnny Football", was a standout at Texas A&M University before playing two seasons with the Cleveland Browns and then being dropped in March.

Known for his partying lifestyle, Manziel has been dropped by two agents this year and media reported he was accused of causing more than $30,000 worth of damage at a Los Angeles home during a party.

(Reporting by Marice Richter Editing by Chris Michaud; and Clarence Fernandez)