Joe Philbin generally prefers to develop rookies slowly. That was what he did in Green Bay - with a lot of success and Green Bay has about the highest % of draft success in the NFL. While some players like Tannehill, Landry and Juwuan James were thrown in the deep end right away because they were ready, most rookies are developed slowly. Some like Jelani Jenkins, Lamar Miller and Dallas Thomas have been given more opportunities after fairly slow NFL starts.
Don't worry about Jordan Tripp. He is going to be very good and I expect that he will be given an opportunity if a LB gets injured or he just does his job on Special Teams and gets more of an opportunity next year.
I was very interested to hear Cam Wake make the comment that the rookie who is the most enquiring and eager to learn from the pros, is Tripp.