Stefanski apparently doesn't agree that Sanders is ready to play, because Flacco is the backup and the other rookie is starting.
The team and coaches that drafted him would know better than anyone. The fact that they would bench Flacco and start a rookie QB that isn't Sanders tells you about all you need to know.
All that said, with the dumpster fire that is the Browns season on offense, Sanders will almost certainly get his chance to play.
I feel for Miles Garrett. HOF level player whose entire career will be wasted on terrible football teams.