Tony Romo is a little more at risk now than he was before.
NFL Network's Michael Lombardi confirmed Wednesday that Dallas Cowboys rookie right tackle Tyron Smith suffered a hyperextended knee, an injury that typically requires two to four weeks of recovery time, meaning he would miss Sunday night's season opener against the New York Jets.
"There are different challenges that we all face every day," Garrett said. "If any of these guys aren't able to play, hopefully the backups understand the value of their opportunity and we can move right along."
Garrett often talks to his players about injury being an opportunity, pointing to players such as wide receiver Miles Austin who have used temporary promotions to become high-profile performers.
Still, this is a bit much -- three expected starters potentially missing for a team that's coming off a 6-10 season just days before heading to New York for a prime-time opener. And on what promises to be an emotionally charged night because of the 10-year anniversary of the Sept. 11 terrorist attacks.
The offensive line already was suspect because it features Smith, fellow rookie Bill Nagy and Phil Costa, a second-year center who'd played just two games on the offensive line. Losing Smith really could make things risky for Romo, especially against an aggressive defense like the Jets have.
Jermey Parnell took over at right tackle Wednesday, but he's more of a project than an NFL-ready starter. A former college basketball player, he played only one season of football, and it was on defense. He switched to offensive line while on the New Orleans Saints' practice squad in 2009. He was with the Cowboys for 12 games last season and was inactive for all of them.
"I go against him every day in practice, so I have a lot of confidence in him," Ware said of Parnell. "They stick him at right tackle, he's going to be a little quicker than a right tackle. He's already used to the speed. He's just got to get used to the bigger guys on that right side powering him."
None of the other backup linemen have much experience at tackle, although newly signed Derrick Dockery played there some early in his career and in college.
Terence Newman didn't practice Wednesday and likely won't play Sunday because of a lingering groin problem, and fellow starting cornerback Mike Jenkins left practice with a knee injury. The Fort Worth Star-Telegram reported that Jenkins hyperextended his knee.
Smith and Jenkins were having MRIs to determine the severity of their injuries and are considered day to day.
Newman and Jenkins are trying to bounce back from miserable seasons in 2010 after both made the Pro Bowl in 2009. They've hardly had a chance to get comfortable in a unit now being run by a new coordinator, Rob Ryan.
Both cornerbacks missed the entire preseason and nearly all of training camp, Newman because of the groin problem and Jenkins because of a stinger sustained Aug. 1. He did some non-contact work in recent weeks, but Wednesday's practice was his first with hitting in pads since the injury.
The Cowboys finished practice with a first-string tandem of Orlando Scandrick and Alan Ball, who started at safety all last season. The only solace for the Cowboys is that the duo received plenty of work in the preseason. Of course, that's not the same as trying to stay with Santonio Holmes, Plaxico Burress and Derrick Mason for four quarters.
"I'm not going to sit here and not say it's not going to be a challenge when you go against those caliber of receivers," Scandrick said. "I'll be ready to embrace the challenge, and I have confidence that my guys will be ready to embrace the challenge."
There is no timetable for Newman's return.
"That's hard to tell," Jones said. "I thought he'd be ready by now. He's a guy who has to have it just right and we want him to be just right."
Jones also said the team isn't sure if backup tight end Martellus Bennett (ankle sprain) will be able to play Sunday. Bennett didn't practice Wednesday.
Several players who had been hobbled returned to practice Wednesday, but were limited. The group includes Costa (knee), Austin (hamstring) and linebacker Bradie James (ankle). Defensive end Marcus Spears (groin) and running back Tashard Choice (knee) fully participated.
The Cowboys also continued to tweak the roster, with recently added Tony Fiammetta -- the only fullback on the roster -- being cut to make room for wide receiver Laurent Robinson.
The Associated Press contributed to this report.