Mettenberger was arrested March 7 in Remerton, Ga., near Valdosta. He is facing five misdemeanor charges including: underage possession of alcohol, disorderly conduct, obstruction and two counts of possession of false identification.
"I'm pretty certain it's going to be a one-game suspension, and all the other internal things that we do that he's in the process of doing right now," Richt said.
Richt has said Mettenberger has shown remorse for his actions, and has taken full accountability in dealing with his punishment.
Richt delayed the suspension announcement for almost two weeks while waiting for more information regarding the incident.
"I'm still waiting," he said. "Really, what I'm looking for is if there's another report that I can get my hands on. A lot of times there is an initial report, and then another one that comes with it, and I just haven't seen that. It may not exist. That's the main thing."
Mettenberger entered spring practice as one of three players hoping to secure the starting quarterback job.
He's still practicing, and seeing time with the No. 1 offensive unit.