PHILADELPHIA - Lost in the euphoria surrounding Sam Bradford's standout performance in Green Bay Saturday night was the realization that the Eagles rebuilt defensive backfield is still a work in progress.

The big problem remains the nickel, a sticky subject because Chip Kelly decided to trade Brandon Boykin to Pittsburgh on the eve of training camp, as asset that, while overvalued by most in Eagles nation, is significantly better than the in-house options currently being discussed.

With high-profile free agent signing Byron Maxwell and offseason star Nolan Carroll having a stranglehold on the starting cornerback positions, rookie sixth-round pick JaCorey Shepherd got the first opportunity to handle inside duties until a torn ACL early in camp interrupted his on-field job interview.

(Listen to John McMullen discuss the Eagles secondary and more)

From there the decision was to speed up second-round pick Eric Rowe's development by giving him repetitions on the inside, a decision that has not paid early dividends. It was  clear in practice that Rowe wasn't comfortable in the slot so the decision was made to kick Carroll inside when five defensive backs hit the field and insert the rookie on the outside opposite Maxwell.

By putting more on Rowe's plate, however, the Utah product started thinking too much and regressed as evidenced by his struggles in Green Bay against Brett Hundley over the weekend.

"I though he did some good things (against the Packers)," Kelly demurred, "but there are also things he needs to improve on."

The fact that Rowe doesn't look ready for extensive action come Week 1 has put other alternatives in the mix.

"There are still valuable reps out there," Kelly said, admitting that the position is still up in the air.

The easiest option would be letting veteran E.J. Biggers handle the slot duties. Biggers, though, also had his difficulties at times against the Packers and a seven-year sample size has tagged the 28-year-old with the label of journeyman for a reason.

"Everybody is just trying to get better," Biggers told 973espn.com when discussing the competition. "The young guys have been doing a great job and we are all just working to make each other better."

That kind of leadership usually doesn't go unrewarded in Chip Kelly's culture-based system but production is also key and if none of the corners prove worthy, it's still conceivable starting safeties Malcolm Jenkins and Walter Thurmond, who both have extensive experience inside, could handle the duties.

Of course, moving either down would mean a third safety would need to enter the contest and the Eagles have less depth there (Chris Maragos, Ed Reynolds) than they do at corner.

Kelly insisted he would like to solidify the plans before game planning begins for the Falcons.

NOVACARE NOTES:

*Kelly did try to temper the hoopla surrounding Bradford's play, admitting the preseason is more about getting young players on film to help teach and evaluate.

*Instead of victory Sunday after the big win in Green Bay, the Eagles held accolade Monday. The coach gave a tip of the cap to nose tackle Bennie Logan, who has been the Eagles best defender throughout the preseason and looks like he is on the verge of a monster season.

"Bennie has really been a disruptive force in the run game," Kelly said.

He also singled out backup offensive lineman Dennis Kelly, claiming the four-year veteran has been very consistent at both guard and tackle. "It's been his best training Camp," Chip asserted. "I'm a big Dennis fan."

Others getting the pat-on-the-back treatment were tight ends Trey Burton, who caught two TD passes against Green Bay despite a broken thumb, and Brent Celek as Kelly is very impressed with how Burton has transitioned to the position while Celek was lauded for his blocking. "He could be the best blocking tight end in the NFL," Kelly said.

*When ever you mention tight ends, Zach Ertz has to enter the conversation and Kelly believes the pass-catching threat could still be ready for Week 1. In other injury news, right tackle Lane Johnson confirmed he has an MCL sprain in his left knee but believes he is on track to start the opener. Outside linebacker Marcus Smith remains sidelined with his hamstring, issue and Kelly admitted  kicker Cody Parkey is dealing with a groin injury. Linebacker Kiko Alonso, meanwhile, will practice this week but no decisions have been made on will play Thursday against the New York Jets.

-John McMullen covers the Eagles and the NFL for 973espn.com. You can reach him at jmcmullen@phanaticmag.com or on Twitter @JFMcMullen.