Cardinals outside linebackers Chandler Jones (front) and Markus Golden are reasons for optimism despite free agent losses.

The writing was on the wall for weeks, but outside panic really set in when the ink spilled onto actual contracts.

With limited salary cap space compared to the rest of the NFL, the Cardinals couldn't afford to get into a bidding war on defensive tackle Calais Campbell and safety Tony Jefferson, their premier free agents who found a robust open market.

They were followed out the door by defensive backs Marcus Cooper and D.J. Swearinger, as well as backup pass-rusher Alex Okafor. Linebacker Kevin Minter is not expected to re-sign, which will leave the Cardinals with five new defensive starters in 2017, and that reality has Cardinals fans worried.

While the loss of several significant contributors can't be construed as a positive, it's probably not the fatal blow some believe.

The Cardinals had less available cap space than other teams heading into free agency because General Manager Steve Keim already paid a premium for several pieces defensively.

Cornerback Patrick Peterson and safety Tyrann Mathieu received their lucrative extensions in past years, while outside linebacker Chandler Jones signed his this month. Money linebacker Deone Bucannon and outside linebacker Markus Golden are on cheap rookie contracts, but were first- and second-round picks and have lived up to that billing.

While the Cardinals have lost some significant players in free agency, it's that remaining nucleus --five talented pieces all 27 or younger – which allows for hope moving forward. Much depends on Mathieu returning to his All-Pro form and Bucannon shaking off an underwhelming, injury-plagued season, but foundational players still pervade the Cardinals defense.

"I don't think we're necessarily looking for quote-unquote franchise guys at each position (in free agency)," Mathieu said. "I think we already have those kind of guys. Really all we need is for our young players to really step up. Play well, play their role well. And then just add veteran guys who understand football and who can really help the younger guys progress as well. If we're talking about cornerstones, I feel like we have those kind of guys at each position."

The Cardinals have replenished the defense with linebacker Karlos Dansby, safety Antoine Bethea and outside linebacker Jarvis Jones. None of the moves made major waves – outside of the nostalgia surrounding Dansby's return – but Jefferson, Swearinger and Cooper didn't come in with much fanfare either.

Jefferson was an undrafted free agent, Swearinger a practice squad signee after getting cut by the Bucs and Cooper via trade for a seventh-round pick.

If Dansby and Bethea have lost a step or if the core five don't play up to their ability, the Cardinals defense could take a step back, but the defensive personnel has been churned before, and the moves have often worked out.

"You've just got to trust and believe in Steve Keim, Bruce Arians and Mr. (Michael) Bidwill," Chandler Jones said. "They do a tremendous job of getting guys that are just absolute monsters."

The high demand for the Cardinals' free agents has made it clear how much individual talent the defense possessed in 2016. In some ways the numbers matched up, as the unit finished second in the NFL in both yards per play (4.8) and yards per game (305.2) allowed.

However, when it came to scoring defense, the sum was lesser than its parts, as the Cardinals gave up 22.6 points per contest, which was 14th in the league and the worst in the Arians era. The 2017 defense could very well be less talented across the board and still finish with fewer points allowed.

Defensive tackle Robert Nkemdiche is one of the biggest keys, because if he can blossom in his second season it will make Campbell's loss easier to digest. The draft is deep defensively, and the Cardinals could find a contributor or two there.

In the end, it will likely come down to the core quintet. Peterson, Golden and Jones were superb a year ago. If Mathieu and Bucannon return to the heights they previously reached, the perceived drop-off may never materialize.

"We lost some important guys, some guys we obviously want to have back, but that's just the business of it," Mathieu said. "Guys want to get paid and take care of their families. But I think if us five or six can really play at a high level, and do what we're capable of doing week in and week out, we'll still be a top-three, top-five defense."