Brian Urlacher has retired after 13 seasons in the NFL. The former Chicago Bears linegbacker tweeted his intentions Wednesday. Urlacher was an eight time Pro Bowler. Urlacher failed to reach a new contract agreement in the off season and he became a free agent. Urlacher was the Associated Press defensive player of the year in 2005 and helped lead the 2006 Bears team to the Super Bowl. He was slowed last season by injuries.