"I am gathering all information and no options have been removed from the table," Tim Younger said when reached by text message Friday morning.
Rudolph was struck in the head with his own helmet by Garrett after the defensive end ripped it off in the final seconds of the Steelers' 21-7 loss.
A city spokeswoman said the prosecutor can't comment because Rudolph hasn't filed a complaint.
The fight started when Garrett took Rudolph to the ground following the quarterback's short pass to Trey Edmunds on third-and-long. Rudolph appeared to attempt to dislodge Garrett's helmet as the two exchanged words. As Rudolph stood up, Garrett ripped Rudolph's helmet off and swung it at him as offensive lineman David DeCastro tried to push Garrett away.
"It was pretty cowardly," Rudolph said. "Pretty bush league."
The incident evoked memories of Tennessee's Albert Haynesworth stomping on the head of the Cowboys' Andre Gurode during a 2006 game. Haynesworth was suspended five games, but Gurode opted against pressing criminal charges or filing a civil lawsuit.
Younger tweeted about Thursday night's incident after the game.
"There are many risks an NFL QB assumes with every snap taken on the field," Younger wrote. "Being hit on your uncovered head by a helmet being swung by a 275-lb DE is not one of them. Tonight could have had a catastrophic ending. The matter will be reviewed thoroughly."
The Associated Press contributed to this report.