Dallas Cowboys cornerback Orlando Scandrick stands on the field during a football practice with the Oakland Raiders on Tuesday, Aug. 12, 2014, in Oxnard, Calif. Scandrick has apologized to his family, teammates and organization for failing a drug test that will force him to be suspended for the first four games of the season. The NFL announced the suspension on Tuesday, Aug. 12, 2014. (AP Photo/Jae C. Hong)
Oakland Raiders quarterback Matt Schaub, center, looks to pass during the team's joint football practice with the Dallas Cowboys on Tuesday, Aug. 12, 2014, in Oxnard, Calif. (AP Photo/Jae C. Hong)
OXNARD, California — Morris Claiborne is likely to skip another preseason game, Brandon Carr isn't close to full speed after missing two weeks of training camp and Orlando Scandrick is out for the first four games of 2014 for a drug suspension.
And cornerback isn't the only unsettled position for Dallas' shaky defense.
The Cowboys are coming home from camp in California with even more questions about the league's most porous defense than when they left Texas three weeks ago.
Claiborne is just the latest issue after missing the preseason opener with knee tendinitis. Now he has a shoulder injury that kept him out of the final camp practice Thursday and was likely to sideline him for the exhibition home opener Saturday night against Baltimore.
"If a guy is not out there, that's not a good thing for our team, but it does provide opportunity for other guys to get reps," coach Jason Garrett said.
"We have certainly had a lot of younger players get the opportunity to show us what they can do, and that's good for your football team."
Carr had an extended absence to be with his mother in the final days of her battle with breast cancer before she died a week into camp. He doesn't figure to play against the Ravens, but should be ready when the regular season starts Sept. 7 against San Francisco.
Scandrick won't play against the 49ers because of a four-game ban for violating the league's policy on performance-enhancing drugs. The Cowboys are trying to get him as much preparation time as possible before he has to stop practicing at the end of the preseason.
A revamped defensive line is missing the two biggest offseason acquisitions — free agent tackle Henry Melton and rookie defensive end DeMarcus Lawrence, a second-round pick.
Melton, who is coming off a knee injury that sidelined him most of last season in Chicago, is dealing with a groin injury but expects to play in the third preseason game at Miami. Lawrence is expected to miss at least half the season with a broken foot.
It's still not clear who will replace Sean Lee at middle linebacker after Lee was lost for the season when he tore a knee ligament in the first offseason practice in May.
Justin Durant has been getting most of the first-team work, but former top 10 pick Rolando McClain was acquired just before camp and will get a long look as a possible starter. That doesn't necessarily mean Durant will be a backup. Both could be on the field alongside Bruce Carter, whose job is far from guaranteed.
"It's amazing how players respond to competition for their job and for playing time," Garrett said. "There are a lot of ways to do this and we've just got to figure out who the best three guys are and who deserves the playing time."
The defense didn't look good at times during camp, particularly against the run, and didn't do much to ease those concerns in a 27-7 loss to the Chargers last week. Most of the defensive starters sat out that game, though.
"One of the issues we've had on defense is we've had a number of our front-line guys have not been in the lineup on a consistent basis," Garrett said. "And that's really on all three levels. On certain days some guys have shown up, some parts of that defense have shown up, other days maybe not quite as good."
NOTES: CB Korey Lindsey and TE Dallas Walker were waived, while DT Zach Minter and TE Asa Watson were signed. Minter spent time on Chicago's roster last season after signing as a rookie free agent. Watson signed with New England after the draft, but was waived Sunday.