Tyron Smith is so young he doesn't turn 21 until nearly Christmas.
Bill Nagy is so unproven he didn't even start every game at Wisconsin last season.
Phil Costa's body of work as an NFL lineman includes two games last year and two this preseason before hurting a knee.
Yet those guys are three-fifths of the Dallas Cowboys' offensive line that will protect Tony Romo in the opener Sunday night, a game that also marks his first real action since breaking a collarbone last October.
As much pressure as that might seem, it's not even the full story.
The Cowboys will be trying to slow a Jets defense that could be more aggressive than usual because their head coach, Rex Ryan, will be looking to show off with his twin brother, Rob, across the field coordinating the Dallas defense. They also have to deal with the setting: a nationally broadcast, prime-time game from New York on a night when the city will pay tribute to the 10-year anniversary of the terrorist attacks.
Can these blockers handle all of that?
"I think we're banking on it," Romo said Monday. "These guys have done a good job coming together. They're starting to jell. They just have to go out and play, do what they've been coached to do. I think we've got a good group of guys. Guys are going to work hard and give it their all out there, and that's all that you can ask."
Smith was the Cowboys' top draft pick and has been at right tackle since he arrived near the start of training camp. Nagy, a seventh-round pick, moved into the lineup at left guard midway through camp.
Costa played center on the first team early in camp when Andre Gurode was hurt. Once Gurode returned, Costa mostly played with the second team. He was injured around the same time the Cowboys decided to cut Gurode and hand him the job. So he hasn't even snapped the ball since earning his promotion.
He did some work Monday and is expected to go practice fully on Wednesday.
"I'm glad they put the confidence in me," Costa said. "I'm just happy to have this opportunity."
The Cowboys decided to get younger and more athletic on the line during training camp, shedding the age, size and contracts of Gurode, Leonard Davis and Marc Colombo. The holdovers are left tackle Doug Free and Kyle Kosier, who has moved from left guard to right guard.
The overall crew remains in flux. Dallas kept veteran guard Montrae Holland and second-year tackle Sam Young when the roster was whittled to 53 players on Saturday, but already has dropped both, replacing them with guard Derrick Dockery, who'd been without a job the entire preseason, and fullback Tony Fiammetta. The Cowboys didn't have a single fullback on the roster.
Garrett said the Cowboys had been keeping an eye on Dockery, an eight-year veteran who lives in the Dallas area.
"He plays with some aggressiveness and some snap to him," Garrett said. "He has some position flex, but more than anything else some veteran experience in the interior of the line."
They can use all the knowledge and experience they can get. The other backups are as unproven as the new starters.
Costa said Kosier helps with many of the calls he has to make, and Romo said he will help, too. The big thing is the on-the-job experience they'll have to get.
"We need to be thinking the same thing," Romo said.
Romo added he's trying to help guide them as much as he can on the practice field and in team meetings. He goes back and forth between pats on the back and kicks in the rear.
"At different times you get on them. You have to. I think that's part of the position, part of what some guys need," Romo said. "Other times, they need encouragement. They're getting ripped three times by a coach, right in a row, they need you to come over and let them know that, `Hey, you're working hard, doing right, you're going to make mistakes. You just have to understand now that you can't make that same one again. You learned it, boom, move on, don't let it happen again."'
Garrett's confidence in the linemen is typical of his outlook for the whole club. After all, they've yet to miss a block or lose a game so far this season.
"When you're zero wins and zero losses with the whole season in front of you," Garrett said, "I think you are hopeful."
Notes: WR Miles Austin (hamstring) appeared close to returning, as are CB Mike Jenkins (stinger) and DE Marcus Spears (groin). The outlook for CB Terence Newman (groin) is less clear. Because Mondays aren't usually a practice day, Garrett said he wanted to err on the side of caution in hopes of everyone being ready Wednesday. ... Waived S Andrew Sendejo wound up with the Jets, perhaps as a way for Rex Ryan to get inside information about his brother's plans. Romo said Rex may be out of luck. "We get out there today and then all of a sudden he's changed all the stuff they were doing before," Romo said. "It's interesting. I think Rob probably thought maybe that was some of it because he changed all his stuff. That was pretty funny." ... The Cowboys filled seven of the eight spots on their practice squad. Six went to players who'd been among their final cuts, including S Akwasi Owusu-Ansah and WR Teddy Williams.