Tyron Smith, 20, isn't showing his age

IRVING, Texas -- It's sometimes difficult to remember that Tyron Smith is only 20 years old.

He can't have his first legal drink until Dec. 12. The Cowboys hope that by then their first-round pick will have cemented the right tackle spot through the first 13 regular-season games and display a future so bright that they won't have to worry about the position for a decade.

Smith is well on his way.

Smith did not miss a day of training camp practice, in part because of the lockout and hurry-up start and finish to the contract negotiations. He started all four preseason games, getting extra snaps in Thursday's loss to the Miami Dolphins while his more veteran linemates rested.

"With all due respect to Marc Colombo -- and I think a lot of him and know what he brought to the table -- I feel as comfortable as I could possibly feel at right tackle with the way Tyron has played," owner and general manager Jerry Jones said. "And it has everything to do with the snaps he's gotten."

But now it starts for real with the New York Jets looming on Sept. 11.

Smith will see things from Rex Ryan's defense that he hasn't seen from Rob Ryan's defense during training camp. Four years ago he was in high school. Now he is protecting Tony Romo and having to do it against one of the NFL's best defenses in front of a national television audience.

"I feel like I'll still be preparing all the way up until game day," Smith said after Thursday's preseason loss. "There's no telling where I am right now. Still preparing."

Smith is 20, but he sounds much older. The words come out of his mouth in a measured and deep tone. The way he carries himself makes him seem more mature, wiser.

Just about every day after practice during training camp he would work with offensive line coach/running game coordinator Hudson Houck on his footwork. On some days DeMarcus Ware would join him. On others it would be Doug Free.

Smith did more kick-starts than a lifelong motorcyclist, and he did it without complaint.

"I feel good about his development from Day 1 to Day 63 or whatever this is," Romo said. "I think you see him continually trying to get better and working hard at it. That's great to see from a quarterback or coach's perspective. He's a hard worker and he's got a bright future."

But the Cowboys need Smith to have a bright present, too, if they want to win in 2011.

It wasn't always perfect in the preseason for Smith. He missed a blocking assignment on a running play against the Chargers. He was beaten on a pass rush here and there. Against the Dolphins he had a false start penalty, his only flag of the preseason.

But when he got his hands on a lineman or linebacker, the opponent had no chance.

The Cowboys haven't started a rookie at right tackle since Rob Petitti in 2005. Petitti was a sixth-round pick that year and won the job almost by default. He was gone the next year, replaced by Colombo.

Smith, the ninth overall pick, has staying power.

"He's the kind of guy where he gets it when he sees it," Romo said. "The more times he can be put in that situation, it'll be good for him. All he can do is work as hard as he can and try to improve because he wants to be great. If he does all that it'll serve him well."

Smith promises to do the work. When Smith was drafted, Jones mentioned how the lineman worked in the family business of cleaning office buildings from the end of practice until late at night every night.

It's no coincidence that he found a house not far from Valley Ranch.

"It's probably eight minutes from the facility," Smith said.

His parents took care of the furnishings while he was in San Antonio and Arlington in July and August.

"I like the way my mom designs," Smith said, "so I told her to go ahead and have fun."

Don't forget, he's only 20.

Todd Archer covers the Cowboys for ESPNDallas.com.