Brian Urlacher, a 13-year veteran of the NFL, announced today that he will be retiring from football. Urlacher has played his entire professional career as a linebacker for the Chicago Bears.

Urlacher played college football at the University of New Mexico, where he set a school record for tackles in one season. He was drafted by the Bears in the first round of the 2000 NFL Draft, and later that year was named NFL Defensive Rookie of the Year.

Urlacher announced his retirement via his Twitter account. He linked to a message that made it clear that, although he could keep playing in the NFL, he feels that he wouldn’t be able to live up to his past performance or maintain his passion for the job. Urlacher goes on to thank all of the people that helped him during his career and states that he has “no regrets.”