OXNARD, Calif. — An already thin and questionable Dallas Cowboys defensive line corps suffered a couple of huge setbacks on the first day of training camp.Defensive end Tyrone Crawford suffered a season-ending Achilles tendon injury and defensive tackle Jay Ratliff was placed on the physically unable to perform list after suffering a hamstring injury during conditioning drills.Cowboys owner Jerry Jones said late Sunday that Crawford will miss the season after he went down on his own in a noncontact drill and was carted off the field Sunday during the first practice. The Cowboys are awaiting an MRI exam on Ratliff.I was actually watching it, team vice president Stephen Jones said. Any time a guy falls like that in a noncontract drill, its not good news. Its disappointing. Crawford is our top young defensive lineman.Crawford was expected to be the primary run-stopping backup at strongside end behind starter Anthony Spencer, who was held out of work on Sunday because of a lingering knee issue from minicamp.Add in Ratliffs situation and the team is scrambling to shore up the depth on the defensive line one day into training camp.Jones said the scouting department was already looking at available defensive linemen in free agency. But the Crawford injury makes it even more acute making even more interesting the teams decision to pass on Florida State tackle Sharrif Floyd in the first round of the 2013 draft, even though it had him rated in the top 10 on its draft board. The Cowboys ended up not taking any defensive linemen in the draft.The good news is that the Cowboys dont believe the Ratliff injury is serious. Still, Ratliffs not being ready to start camp is not ideal after he missed 10 games last year with various injuries. He had plantar fasciitis in the 2012 off-season, sprained his ankle in the preseason and then needed surgery late in the season to repair a sports hernia, which put him on injured reserve.Well just evaluate that as we go with Rat, Cowboys coach Jason Garrett said. Rats had a few different things going on over the last year that hes dealt with. He has worked very hard in his rehab. He wanted to run the test [Saturday] just to see where he was to see if he can come back to practice as early as possible. So he is getting an MRI done [Sunday]. We will evaluate what that situation is and make our best decision with him.Players are eligible to come off injured lists at any time before the season starts.But the Cowboys are excited about having him as their 3-technique in the Tampa 2 defense being installed by Monte Kiffin. They believe he is a good fit for the defense.He got a lot of good work for us in the off-season, very smart, great veteran football player, defensive line coach Rod Marinelli said. Just cant wait to get him back.Other injuriesJoining Jay Ratliff on the sideline to start camp are starting guards Mackenzy Bernadeau and Nate Livings. Bernadeau is on the physically unable to perform list because of a tweaked hamstring during conditioning drills while Livings starts on the active/non-football injury list because he suffered a foot injury before camp.Long snapper L.P. Ladouceur (calf), guard Ronald Leary (calf), center/guard Ryan Cook (conditioning), tackle Demetress Bell (conditioning) and receiver Lavasier Tuinei (conditioning) were put on the active/non-football injury list.Bell, Tuinei and quarterback Alex Tanney were signed to the roster to fill three of the teams open roster spots. Bell has played five NFL seasons, four with the Bills and last year with the Eagles.Its the continuation of a frustrating turn with the Cowboys for Bernadeau, who missed most of training camp last year because of knee and hip injuries.Bernadeau had hoped for a fresh start in 2013.I let myself down, Bernadeau said. My whole point was being here on time and being prepared to compete, so Im more frustrated than anybody. Its frustrating. Its the second year in a row not starting off camp. You want to be out there with team, but you still have to be healthy.Bernadeau said the injury is minor and believes he will return soon.But its a huge setback for a Cowboys offensive line that is also beginning camp without Livings and top backup Leary.David Arkin and Kevin Kowalski worked with the first team at guard on Sunday.Unfortunate, but thats the way the game goes, offensive line coach Bill Callahan said. A lot of guys stepped up into those positions and roles. Well get them back in a couple of days, I think. Its one of those things. You cant plan for it. You just adjust and adapt off it.
Clarence E. Hill Jr., 817-390-7760 Twitter: @clarencehilljr