After nearly two full weeks of training camp, the Dallas Cowboys take their first real preseason test against the San Diego Chargers on Thursday night at Qualcomm Stadium. 

The bar typically isn’t set very high for the preseason opener, but it will serve as a litmus test for some of their offseason moves, as head coach Jason Garrett looks to piece together his 53-man roster. The defending NFC East champs spent the offseason sprucing up one of the league’s worst pass rushes, and further solidified the secondary, defensive line, and linebacker corps in the draft and free agency.

There has been no shortage of scrutiny on the defense after some struggles in recent practices.

“We challenged our defense [Saturday] in our meetings, explained to them why they were dominated,” Garrett said. “There were a number of different reasons, and we tried to address those and be crystal clear as to what we want and what we expect, and we anticipate them to respond the right way.

“It was not a perfect day for the defense by any means. But they certainly responded well and played a heck of a lot better.”

Garrett will no doubt pay close attention to some of the key additions like Greg Hardy and second-round draft choice Randy Gregory. But the Cowboys could use more depth in the secondary, which means players like Tyler Patmon and Joel Ross need to make an impression before rosters are reduced to 75 players on Sept. 1, and then 53 players on Sept. 5.

Let’s take a look a three potential storylines to watch during the opener.

New Pass Rushers

The pass rush was Dallas’ Achilles heel last season, ranking No. 28 in the league with only 28 sacks, which in turn led to trouble for the secondary, which was 26th in passing yards allowed. Hardy and Gregory are expected to produce right away, but Dallas needs a third and possibly fourth option even after Jeremy Mincey ended his holdout and reported to camp Sunday. So the Cowboys spent their fifth-round pick on defensive end Ryan Russell.

Lots of eyes will be on Russell. He tallied only 8.5 sacks the last three years in college, but does have the physical attributes to be great. At 6-foot-5 and 267 pounds, the former Purdue standout showed blazing speed at the combine with a 4.75 40-yard dash and he beat last season’s star rookie offensive lineman Zack Martin with a spin move, according to CBS Dallas. Russell’s also making the transition from the Boilermakers 3-4 system to Dallas’ 4-3, and it could better suit his skills.

Rookie Damien Wilson may be crucial for defensive coordinator Rod Marinelli in 2015. Dallas may rely on the weak side linebacker with Sean Lee continuing to battle back from a torn anterior cruciate ligament.

Starting Safety

Free safety J.J. Wilcox earned the starting spot last year, a little over a year removed from playing wide receiver in college. It’s an impressive transition, but the Cowboys could also see where first-round pick Byron Jones fits at safety, as well as undrafted free agents Tim Scott and Ray Vinopal.

Jones is currently behind corner Brandon Carr on the depth chart, and he could usurp that role or even Orlando Scandrick’s. But it’s Wilcox whose starting job might be the most in jeopardy. Scott certainly has the experience to make an impact during camp. He spent all four years at North Carolina as a defensive back and pulled down eight interceptions with 29 passes defensed.

Tight End

Seventh-round pick Geoff Swaim hasn’t been “flashy” during camp, according to ESPN, but he’s been consistent behind starters Jason Witten and Gavin Escobar and fellow second-stringer James Hanna. Its possible Dallas keeps four tight ends, especially with Witten now 33, but Swaim won’t be expected to make plays down field. How well he blocks at the line, with an excellent 6-foot-4, 250-pound frame, may secures him a spot on the 53-man roster.