For every concusion that was diagnosed I bet he has at least one that went under the radar.
I disagree, it depends on what level of concussion severity it was and it should be his decision.
For example I have had 3 mildly severe concussions:
1. In a high school game, level 2, I took on 2 blockers and got knocked out, but didn't know it. To this day I don't remember the whole 4th quarter including intecepting a screen pass for a TD. A news reporter asked me about it after the game and I had no idea what he was talking about.
2. Sledding accident freshman year at ISU was a high level 2. Did a backflip on a saucer sled off a ramp and cracked my head on ice. I don't remember anything for 1 hour after, including walking back to the dorm and having my friends clean the blood off my face.
3. Missouri my Senior year, got a level 2 in the first quarter. And without the coaches and trainers knowing I put myself back in on special teams in the 4th Quarter when the headache went away.