Casillas, who missed the eighth-ranked Badgers' first two games because of a sprained medial collateral ligament in his left knee, was stopped by a university police officer on Aug. 24 just after midnight. A breath test showed his blood alcohol concentration to be 0.15 percent, nearly twice the legal limit of 0.08.
Casillas, 21, received three citations -- first-offense drunken driving, driving with a prohibited alcohol concentration, and driving with two persons on a mo-ped.
According to the Wisconsin State Journal, Badgers coach Bret Bielema said he already has disciplined Casillas.
"We handled that the same way as any alcohol or drug [violation]," Bielema, who did not give additional details, told the newspaper.
Bielema said the case does not fall under the UW student-athlete discipline policy.
Casillas is scheduled to appear in court on the citations on Friday. Wisconsin (3-0) has this weekend off before visiting Michigan on Sept. 27.