Pickett, Najee, Harmon, Fautanu, Jones, Frazier, Beanie, McCormick, Porter, Black and others. All have been playing since drafted or within a few games. I dispute your entire premise. Not all have stuck but to say he doesn’t play rookies is totally disingenuous.
Edit: Add in Payton Wilson who got more and more time last year as well. If a rookie isn't playing, I bet there is a pretty good reason why not. Bruener is being used as a special team's ace. This class alone we will have had three rookies start games by the end of this week. Black, Harmon and now Captain Jack likely.