Miles, a sophomore, was considered the heir apparent to Keith Price as the Huskies' starter.
The Seattle Times reported that Miles was linked to two Feb. 2 assaults on campus after the Super Bowl. Myles was not ultimately charged.
Miles had been suspended for spring practice but was reinstated to the program in May.
“I thought it was appropriate that he was going to miss the first game as well,” Petersen told reporters during
Sophomore Jeff Lindquist and redshirt freshman Troy Williams from Harbor City Narbonne High will compete to start the opener.
"That quarterback position is wide open," Petersen said.
Miles' spring suspension put him "behind the eight ball," Petersen said, but Miles will participate in training camp and could emerge as the starter as the season progresses.
"He's done everything right, without question, or he wouldn't be with us," Petersen said. "Guys make mistakes, we all know that, certainly in that age group. Always say, hey, the age group we're dealing with, for the most part, is the dumbest age group in America.