Conversation so far:
What year did Rod Woodson retire from the NFL?
From his retirement in 2003 to February 2011, Woodson worked as an analyst.
What NFL team did Rod Woodson retire from?
On July 28, 2004, the Oakland Raiders released Woodson after he failed a physical after undergoing knee surgery.

Question: Why did he retire?
Self-contained rewrite: Why did Rod Woodson retire from the NFL?