Earnhardt, Jr believes concussion happened at Michigan

Dale Earnhardt Jr. at Michigan before crashing

Dale Earnhardt Jr. said his doctors believe his concussion-like symptoms started with his June 12 crash at Michigan International Speedway. "Obviously with my history of concussions, knowing the event I had in Michigan, that wreck right there is where they believe I picked up this issue," Earnhardt said Monday night on his weekly Dale Jr. Download podcast.

"I didn't feel anything that next week. The off week, I went to Germany (on vacation), went to Sonoma, ran good, felt awesome. It was strange these symptoms came out of nowhere. But we started doing a lot of digging, and they seem to feel confident this occurred in Michigan."

"This is scary for me because of the way it's been different. I'm having balance issues. I've never had balance issues before. The eye issues with the stability, I've never had that before. It started very slowly, gradually and continued to progress until it stopped and stayed where it is. I don't know what tells me about how long this process is going to be. I felt I had a good understanding of concussions in the past, but this is certainly a new one. They all have different symptoms and own time and length of recovery is different." NBC Sports