IRVING — Expectations can’t be much lower for the Dallas Cowboys’ defense heading into Sunday’s season opener against San Francisco.After finishing last in the league in yards allowed per game, worst in team history and third worst in league history a year ago, the Cowboys have done little to improve the talent base.Uncertainty and lack of continuity because of injuries and turnover are the main reasons normally optimistic owner Jerry Jones said the Cowboys have an uphill battle in 2014.Defensive tackle Henry Melton, the team’s prized free-agent signee, missed the entire preseason because of injuries. Defensive tackle Terrell McClain, another free-agent signee expected to a big part of the rotation, might not play Sunday because of an ankle sprain that sidelined him the entire preseason.Defensive end George Selvie, the leading returning pass rusher with seven sacks, will play in the opener with an injured shoulder that has bothered him throughout the preseason.That injury list doesn’t include rookie defensive end DeMarcus Lawrence, the second-round pick from Boise State who was supposed to replace the departed DeMarcus Ware as the primary pass rusher. Lawrence is out for the first eight weeks with a fractured foot.The linebacker corps is in a state of flux with position changes and new starters in the past two weeks.Cornerback Orlando Scandrick, the team’s best defensive player in training camp, is suspended for the first four games.“It’s challenging, but you’ve just got to work through it,” defensive coordinator Rod Marinelli said. “That’s the cards we’re dealt and you just work through it. Especially in my role, I think leadership is probably the No. 1 thing, and you lead from the front.”Things are so bad that coach Jason Garrett had to resort to generics when asked what he liked about the defense.“You know, a lot of different things,” Garrett said. “We have a lot of different combinations of guys that have come from a lot of different places. We like the competition. We think that’s good, and we think everybody is benefiting from it.”Marinelli said the defense has gotten better in learning its concepts after a preseason in which the Cowboys allowed the most rushing yards in the NFL.The Cowboys have added two defensive ends since final cuts Saturday.“We’re getting a little bit healthier, not a whole lot, but we’re getting some guys back,” Marinelli said. “They’re going to play hard, and we just have to be effective and we have to have eight guys in a rotation and keep fresh and go.”Witten’s roleAs the Cowboys move to balance their attack by running the ball more, something will have to give in the passing game.That something could be a decline in the number of receptions for perennial Pro Bowl tight end Jason Witten, who has been quarterback Tony Romo’s most trusted and prolific target for much of the past decade. He has had seven consecutive seasons of 73 or more catches and 10 consecutive with 64 or more.“We want more consistency in our offense,” Witten said. “We want to run the ball, and everything falls after that.”Witten acknowledges when the Cowboys do pass in this season that getting the ball to game-breaking receiver Dez Bryant will be the primary focus because he “is such a huge playmaker.”Witten is secure with his place in history as the Cowboys’ all-time leading receiver and a possible Hall of Fame candidate as a tight end.“I want to be the best player I can be and have high expectations, but at the same time I want to win football games,” Witten said.Injury updateWide receiver Terrance Williams (back) and guard Zack Martin (foot) were added to the injury report Thursday.According to a source, Williams missed practice with a bruised back. He was held out only for precautionary reasons. He should do something in practice Friday and be ready to play against the 49ers on Sunday.Martin, the rookie first-round pick from Notre Dame, was limited in practice. But the foot injury is not deemed serious, and he should play against the 49ers.
Clarence E. Hill Jr. 817-390-7760 Twitter: @clarencehilljr