Smith mentions how he typically chips his teeth a couple of times each season as if it's no big deal. Just part of the job as a menacing defensive lineman who refuses to wear a mouth guard because it makes for tough breathing.
The 11th-year defensive tackle and Defensive Player of the Year candidate plans to take the time to get all his teeth fixed once his stellar career is over.
For now, he is all about leading San Francisco's top-ranked defense into the first playoffs for this once-proud franchise in nine years. The 49ers (11-3) have a short week to get ready for their game Saturday at NFC West rival Seattle after beating Pittsburgh on Monday night.
Smith will play a key role in trying to keep a pair of impressive defensive streaks going against the Seahawks and running back Marshawn Lynch.
The 49ers are the first team in NFL history to not surrender a rushing touchdown through the first 14 games. They've gone 36 straight without allowing a 100-yard runner.
''We take pride in stopping the run. We don't get into that. I really don't know how many it's been to be honest with you,'' Smith said. ''It's just one of those things. We're in the business of trying to win a football game, not necessarily streaks or stats or anything like that. The main thing is stop the run and give our team a chance to win, and that's what we're all about.''
It's a no-nonsense approach that earned Smith the team MVP title from coach Jim Harbaugh on Tuesday.
While Smith doesn't lead the NFL, or even the NFC, in defensive categories or have the flashy numbers of others in the Niners' locker room, it is his constant presence wreaking havoc on opposing offenses that has made him one of the best defensive linemen in the game.
During the lockout this summer, Smith took the lead for the defense for player-organized workouts at nearby San Jose State.
''I think we've taken another step. We have more steps we can absolutely take,'' Smith said of his unit. ''We've put our team in a position to win a lot of games.''
Smith doesn't need praise for his role in this year's remarkable turnaround. He lets his teammates have the spotlight.
All the while, the 32-year-old Smith – who spent his first seven NFL seasons with Cincinnati before joining the 49ers as a free agent in 2008 – owns a streak of 169 straight starts, fifth among all active players, third among defensive players and tops for defensive linemen.
''Justin, man, he's a blue-collar guy who's a phenomenal player and he's going to play every snap,'' linebacker Patrick Willis said. ''He doesn't care how he looks. I tell him all the time, `Justin, can you get some pants?' and he says, `Man, I'm a blue-collar guy, I just go out there and play.' He's a guy a lot of people don't talk about.''
Smith is just the third player in franchise history since sacks became an official stat in 1982 to make at least six in four straight seasons, from 2008-11 – joining Charles Haley, who did it in six consecutive years from 1986-91 and Dwaine Board from 1983-86.
''There are always three or four plays every game where he just knocks the socks off somebody,'' said Monday Night Football analyst Ron Jaworski, a former NFL quarterback and. ''Sometimes we don't give him enough credit for being a great player. We always talk about his effort, but he has great skill.''
Months ago, offensive lineman Alex Boone described Smith's signature ''chop-to-bull'' move – when Smith chops an opponent's arm and drives his shoulder in before violently shoving the player back. Smith, the fourth overall draft pick in 2001 out of Missouri, has an uncanny combination of speed and explosiveness that allows the 6-foot-4, 285-pound defender to swat down passes or get in the middle of plays while coming almost out of nowhere.
''When he wants to hit the jets, you'd better be ready for it. He's very famous for the chop-to-bull, which kills everybody,'' Boone said. ''Once you set your hands on him you've got to be very firm with him, as opposed to another defensive end where you just kind of put your hands on him. ... If you watch the film, he gets everybody with it. It's pretty impressive. You know it's coming but he still gets you on it somehow. It's unbelievable.''
Seattle has had its share of up-close-and-personal experiences with Smith.
''Just be prepared for the bull rush,'' Seahawks center Max Unger said. ''He's been playing football for a long time and he has a very distinct style of play that's very effective to say the least. We've got to have our chin straps buckled up.''
Seattle coach Pete Carroll calls Smith, ''the guy that you can't miss him when they play, he's so tough and he's so aggressive. He does not stop.''
Yet for those unfamiliar with Smith, it takes watching him regularly to truly appreciate his constant presence.
Even new defensive coordinator Vic Fangio acknowledges he didn't fully realize the extent of Smith's talent until he began coaching him every day during training camp.
''Not as (well known) as he should be,'' Fangio said Wednesday. ''I can use myself as an example there. I knew Justin Smith was a good player but until I got here and was actually involved in coaching him and seeing him play day to day and game to game, he's better than my perception was. He's probably having his best year he's ever had. No. 1, he's got great talent and, 2, he's tenacious. He loves to play the game of football the right way.''
Smith, nicknamed ''Cowboy'' for his Missouri roots and blue-collar mantra, has talked about having a ranch one day.
Defensive line coach Jim Tomsula hopes that's a long time from now.
''I love the guy,'' Tomsula said. ''He is unique, man, he's a unique cat. He is. He's extremely intelligent. We laugh a lot because we talk about how he's a high-motor guy. A lot of times you hear high-motor guy and that's a guy that's maybe not real talented but he works real hard. Let's not forget this guy comes out and he's a phenomenal athlete. We're always laughing when everybody busts his chops, `high motor, high motor.' He's high motor but he puts it with a whole lot of ability, and then you put a mindset to it.''
This 'Cowboy' one Smith everybody should know
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