Authorities say Coprich, 20, tried to sell between 10 and 30 grams of marijuana to an undercover officer on April 16.
Coprich is due back in court May 22 after being released on $2,025 bail and faces up to three years in prison if convicted on the Class 4 felony charge.
"Marshaun has been suspended, effective immediately," Illinois State head coach Brock Spack said a statement, via the Chicago Tribune. "Though we are disappointed that he is in this situation, we will let the process continue before a final decision is made."
Coprich, a 5'9", 205-pound senior from Victorville, Calif., led the Football Championship Subdivision in rushing last season with 2,274 yards, scored 27 touchdowns and was named the Missouri Valley Conference offensive player of the year.
Coprich finished fifth in the voting for the Walter Payton Award, given to the best player in FCS football.
He helped lead the Redbirds a 13-2 record and a spot in FCS the national championship game, where Illinois State lost 29-27 to North Dakota State. Coprich had 16 carries for 106 yards in the game.
- Scooby Axson