Since coming into the league in 2007, Rice has faced a plethora of injuries including concussions which he says is his main reason for retiring. Here is an official statement from seahawks.com
"I was just thinking about things I've been through in the last few years," said Rice, a big-play wide receiver who signed with the Seahawks in 2011 after playing his first four seasons with the Minnesota Vikings. "I've hit the ground a number of times. I have quite a few injuries. It's something I've always battled through and came back from.
"But I just figure at this point I have the rest of my life ahead of me and I want to be able to function and do things later down the road."
At just 27 years old, we will always ask "what if" when thinking of Rice's career. Still, during his short tenure in the league, he did make some great plays. Here's to you Sidney, good luck with whatever comes your way next.