Here's a collection of comments from around the league about longtime Bears linebacker and his retirement after 13 seasons in the NFL:
"When you draw up the package you look for in a player, Brian is your model. He redefined the 'mike' backer position with rare size and incredible speed. The Mike backer is usually a two-down player. In Brian's case, he could dominate on any down. He would have led the league in sacks if he were in a 3-4 scheme. His skills were such, along with his size, he would have been an all-star in any scheme. He was a great teammate, not a selfish bone in his body. He spoiled us. Football is a better game because of him. He'll be missed, but not forgotten." -- Jerry Angelo, former Bears general manager
"To go up against a guy like that in practice every day and in training camp for seven years, it's quite funny the things that he does on the field, the things he says. He'll make a defensive call or make a call check and then he'll yell out a joke at the same time. That's the kind of guy he is. He's about his business, but he likes to have fun. And likes to make sure that his teammates are working hard, but at the same time that you are having fun. He's taught me a lot of things, just from watching him. He was one of the guys I looked up to in the locker room from Day 1 of me stepping into Halas Hall. I knew that if I had the work ethic, the same attitude and mentality of a Brian Urlacher that I would last a long time in this league." -- Jason McKie, former Bears fullback
"Congratulations @BUrlacher54 on your retirement. You were one of the fiercest players I ever stood across the line of scrimmage from." -- Brett Favre on Twitter
""A great player in the NFL. And he was a really good competitor. He was a guy that you respected from a coaching standpoint because of what he could do on the field. I know he was respected by players and amongst his peers. A different kind of linebacker. There's not many guys that are 6-foot-4 playing middle linebacker. It's generally a position that shorter guys have had a lot more success, guys like Mike Singletary, who was probably 6-feet tall. Ray Lewis, about the same way. Urlacher in a lot of ways changed the position. His range at the middle linebacker position, the speed that he played with. He was super fast. The guy played free safety in college. A long career. Was a turnover machine. You always worried about him, where he was on the field, the turnovers he could create, the way he could change a game. He was good for the NFL, he was good for the game of football and it's been a great career for him." -- Jim Schwartz, Lions head coach
"He meant a lot to me because not only was he a great player, but a great person. For as big of a celebrity and well known as he is, he was so down to earth. He would help anyone with any questions they had about the defense. Brian was probably one of the smartest players I have ever played with. A lot of times he would call out the opponent's offensive play before they even ran it. I am very fortunate to have played with one of the greatest linebackers in NFL history." -- Corey Wootton, Bears defensive end
"He treated everyone with respect whether they were a 10-year vet or a rookie on practice squad. If you ever needed anything Brian was there for you. It was great having the opportunity to play with him and his leadership will be missed." -- Chris Conte, Bears safety
"He was a big kid at heart on the field. He was one of the most friendliest guys on the team, but was listed as one of the most feared guys in the league. He was always upbeat." -- Devin Hester, Bears' kick returner, to ChicagoBears.com
"He looks like he could play another two years, but he made a good decision and he had a great career. You don't look back and say, 'what if, what if.' When they got a new general manager, they got a new coach, you knew they were going to go a different way. That's all. They felt they were better off to go without him. Whether it's fair or not, it doesn't matter. That's just what happens." -- Mike Ditka
"I was a little bit surprised because I know he's been shopping around a little bit and wanted to continue to play a little bit longer. But since he's made that decision, I know he thinks it's right for him. I'm going to be disappointed not to watch him play anymore. ... The way he played the game got everybody to look at him as a leader. He relished that role." -- Rocky Long, Urlacher's coach at New Mexico
"I was very fortunate to coach such a great person, player and leader, on and off the field. The nine years with Brian were the most rewarding coaching experience of my career. Not only did I challenge him daily, he helped me become a better coach and person. He will go down in history as one of the best middle linebackers in NFL history and is a future Hall of Famer. He revolutionized the game as far as middle linebacker play." -- Bob Babich, the Bears' former LB coach
"It has to come to and, but maybe you think that he could have played forever, but you know that won't happen. I'm sad to see it end. But I'm very proud of Brian, not just the things that he accomplished on the football field, but an awful lot off the football field. He's a great role model. He's a great father. He has a lot to be proud of in those regards also." Speedy Faith, Urlacher's high school football coach in Lovington, N.M.
"Played against him numerous times and always clowned around with him before and after the game. Phenomenal player. You speak about a guy that came out of New Mexico as a safety and moved to middle linebacker and dominated the position for so many years. Eight-time Pro Bowler, 13-year pro, just a guy I looked up to, a magnificent athlete and the game is definitely going to be different without him but he laid some good work." -- Stephen Tulloch, Lions LB
"The thing I loved about going against Brian was the conversation between plays, between series, during TV timeouts. I just have a ton of respect for him and wish him nothing but the best. I'll miss him out there." -- Aaron Rodgers, Packers QB, on the "The Jim Rome Show"
"When you watched them play, the ability to line up with four our five different defensive calls . . . then the instincts, the anticipation of really knowing your offensive scheme inside and out. You could tell he was a true expert, studied the offenses. It was something we always had to make sure we had to change up because he was a very smart, very instinctive player. Made a lot of big plays in our games that we played over the last seven years against the Bears. I'm not going to miss playing against him, that's for sure." -- Mike McCarthy, Packers head coach, on SiriusXM's NFL Radio
"You were who we thought you were. Congrats." -- Arizona Cardinals Twitter