Turbin, who was running drills with the Colts' first-team offense in practices this offseason, started one of the six games he appeared in with Indianapolis last season, rushing for 53 yards and a touchdown.
With the team parting ways with veteran running back Frank Gore this offseason, Turbin was expected to see an increased role in the Colts' backfield. He's expected to battle Marlon Mack, Christine Michael, Josh Ferguson and rookies Nyheim Hines and Jordan Wilkins for carries, but the suspension hurts his chances of rising to the top of the in-house competition.
"Unfortunately, I have made a mistake," Turbin said in his statement. "A mistake that will not only have personal consequences but will affect the Colts organization, an organization that I am extremely appreciative to be a part of.
"For that, I'm truly sorry."