PHILADELPHIA (973espn.com) — Sam Bradford is obviously the headline but safety Walter Thurmond might be the most interesting case study in the Eagles' impending free-agency class.

For all the criticism Chip Kelly received for his personnel moves, signing the veteran defensive back to a make-good, one-year, $3.25 million deal before last season proved to be a prudent decision as the former cornerback gave Billy Davis exactly what he craved on the back end next to Malcolm Jenkins, a second option with actual ball skills.

It didn't necessarily translate to great success for Davis' entire defensive unit but so much of those issues could be traced to Kelly's underlying up-tempo offensive philosophy, which prevented his defense from sustaining any kind of statistical success.

On an individual basis, however, there wasn't really much to criticize regarding either Jenkins, who earned a Pro Bowl nod, or Thurmond, who snared a team-high three interceptions.

The biggest concerns with Thurmond entering the 2015 campaign were durability and whether or not the ex-slot corner could hold up in run support on the back end.

Both were answered in the affirmative as the Oregon product started all 16 games, a career-high for him, and played in 99 percent of the team's defensive plays, an astounding 1,200 due to Kelly's stubborn insistence that time of possession means nothing.

While not Brian Dawkins as a thumper, Thurmond also amassed career bests in tackles (76), tackles for loss (6.0) and sacks (2.0) and acquitted himself quite well as a tackler.

Although, like a lot of Eagles defenders, Thurmond's play slipped as the season wore on, of the 88 safeties who played enough to be rated by Pro Football Focus, Thurmond came in at No. 26, a tremendous complement to Jenkins, who was stationed behind only Minnesota's Harrison Smith.

That sure seems like a guy in line for an extension but the move away from Davis' 3-4 scheme and into Jim Schwartz's 4-3 means Philadelphia will be looking for different skill sets at certain positions. And while the old designations of free and strong safety are outdated in today's game, there's little question that the Eagles' new defensive coordinator would prefer to have a better balance between a coverage safety and a more in-the-box type.

In that scenario, the versatile Jenkins would be the coverage guy and Philadelphia would be in the market for a more physical alternative as his running mate.

Of course, just because that's the ultimate desire doesn't mean the Eagles can pull off everything they want to do from a personnel standpoint in one offseason so keeping a proven producer would hardly be the worst thing in the world.

There are a number of dominoes that could fall in such a circumstance. Thurmond could stay put next to Jenkins or move back to nickel cornerback, something which would take the difficult dual-role Jenkins played last season (safety and the slot) off the table.

Schwartz could also get a look at Eric Rowe and deem that the promising second-year player is better suited for the safety position, opening up a starting slot outside the numbers.

The biggest stumbling block in a potential Thurmond return, though, is of course money and what he could potentially get outside the organization if he actually hits the open market.

Shortly after the season ended, Thurmond said he was open to returning to Philadelphia but admitted it's not all that likely because the potential cap number might be too rich for the Birds, which sure sounds like a hometown discount isn't in play.

The Eagles are expected to talk turkey with Thurmond's representation, Lagardere Unlimited, at the NFL's scouting combine later this month.

-John McMullen covers the Eagles and the NFL for 973ESPN.com. You can reach him at jmcmullen44@gmail.com or on Twitter @JFMcMullen