I really wish I had some insiders from that era, before the last season when the defense quit, Cosgrove's defense kept us in so many games while the offense was figuring it out. We went to the Championship game in KC with an average offense and a great defense. The athletes were there, they busted their butt for him for multiple years and then the bottom fell out for some reason in year 4.
Now back to Coleman, haven't heard how severe his concussion is, and don't think he's played the necessary games to burn a RS. At this stage, with this QB play, it makes sense to shut him down for the year, learn the playbook, become a good to great route runner and work to be a viable threat with hopefully an improved QB and line play next year.