Gontarek has been charged with unlawful possession of marijuana and evidence tampering.
"We will continue to monitor and respect the legal process and take further action as warranted," athletic director Mark Benson said.
Gontarek was the Great Danes' leading receiver last season with 58 catches, 687 yards and eight touchdowns. He was a finalist for the Jerry Rice Award, given to the top freshman in the FCS.
The Maryland native, who is also the team's top punt returner, was off to a relatively slow start this season with 16 catches for 181 yards and two TDs.