Smith doesn't mind the nickname, but he says his teammates took the easy road.
"They saw my cowboy boots above my locker," Smith told 49ers.com. "Not real original guys who come up with 'Cowboy' from the cowboy boots, but I like it."
In fact, the nickname fits the defensive tackle perfectly. His work ethic has been praised by the 49ers coaching staff, and younger players try to emulate his every move.
Smith, now in his 13th NFL season, has frequently shunned notoriety, an attitude shared by the rest of the defensive line.
Making the playoffs – something Smith was only able to do once while with the Cincinnati Bengals – is not something he takes lightly.
The 49ers could earn their third consecutive playoff berth as early as Sunday if the Arizona Cardinals lose to the Seattle Seahawks. But the 49ers wouldn't mind waiting to celebrate on “Monday Night Football,” after the final game at Candlestick Park.
"I've played a long time and I've played a lot of years without being in the playoffs," Smith said. "It's hard to get in there. It's designed that way for a reason. The way the draft is set up, it makes it that much harder for you to get back. It's an honor to get in and it's hard to win. I don't take any of them for granted."
The 49ers defense has held opponents to just 50 points in the last four games, reaching their goal of allowing 17 points or less in each contest.
Smith believes the 49ers are peaking at the right time, something he knows will be crucial in order to make a deep run in the playoffs.
"I think we're playing pretty good football right now defensively," Smiths said. "I think there are a couple areas where we can improve moving forward. Hopefully we can start peaking right before we get in the playoffs."
The final game of the year will be memorable for Smith; it’s the last game at the stadium he's called home for six seasons. Smith may have grown up in Missouri, but he rooted for the team that was on top.
"There's been a lot of great memories there," Smith said. "I enjoyed it. It's a great place. The one time I came as a visitor, I enjoyed from the aspect of the glory days. I grew up as a Niners fan – Joe Montana, Jerry Rice. It's fun to play there."