India, June 2 -- Detroit Lions center Frank Ragnow, 29, has announced that he is retiring from the NFL. The four-time Pro Bowl selection, who was key to coach Dan Campbell's Lions revival, made the announcement on Monday, June 2, in an emotional Instagram post.

"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. 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," Ragnow wrote on Instagram.

He added, "I have given this team everything I have and I thought I had more to give, but the reality is I simply don't. I have to listen to my body and this has been one...