Detroit Lions center Frank Ragnow, a four-time Pro Bowl selection, announced his retirement on social media on Monday.
"These past couple of months have been very trying as I've come to the realization that my football journey is ending and I'm officially retiring from the NFL," Ragnow posted to Instagram. "I've tried to convince myself that I'm feeling good but I'm not and it's time to prioritize my health and my families future. I have given this team everything I have and I thought I had more to give, but the reality is I simply don't.