FRISCO, Texas -- Except for the Super Bowl champion Tampa Bay Buccaneers, who are bringing back all 22 starters from the 2020 season, change is constant in the NFL. When you have a defense that was as porous as the Dallas Cowboys', change was more than needed. It was craved.

When the Cowboys' defense allows 473 points, the most in team history, and 2,541 rushing yards, the second most allowed in team history, you can't simply run it back.

The Dallas makeover on defense started with the hiring of coordinator Dan Quinn in January, continued into NFL free agency, where the Cowboys signed five defenders and moved through the 2021 NFL draft in which eight of their 11 selections were on Quinn's side of the ball.

"The thing about us is not only did we create competition, we created it at every level, pretty much every position," Cowboys coach Mike McCarthy said. "it's exactly what we're looking for. We needed it."

Of the 13 defensive players who either started or played in more than 40% of the defensive snaps in the Cowboys' 2020 season finale against the New York Giants, six are gone. Sean Lee and Tyrone Crawford retired. Aldon Smith signed with the Seattle Seahawks. Chidobe Awuzie signed with the Cincinnati Bengals. Xavier Woods signed with the Minnesota Vikings. Eli Ankou remains unsigned.

LIVE: Defensive coordinator Dan Quinn press conference! #DallasCowboys https://t.co/SGlq4gbdBq

— Dallas Cowboys (@dallascowboys) May 2, 2021

The Cowboys have brought in free agents, including defensive ends Carlos Watkins and Brent Urban and safeties Keanu Neal, Damontae Kazee and Jayron Kearse. The draft brought in LB Micah Parsons (first round), CB Kelvin Joseph (second), DT Osa Odighizuwa (third), DE Chauncey Golston (third), CB Nahshon Wright (third), LB Jabril Cox (fourth) and CB Israel Mukuamu (seventh).

Whether an intended message or not, those remaining from last year's defense would be wise to take note of the overhaul. In other words, rent, don't buy, unless your contract is such that it would be difficult for the Cowboys to make a move.

The futures of linebackers Leighton Vander Esch and Jaylon Smith have been much discussed since the addition of Parsons and Cox. The additions of Neal (who will play linebacker, too), Kazee and Kearse put safeties Darian Thompson and Steven Parker on notice.

At cornerback, Saivion Smith was the first to be released after the selections of Joseph and Wright. Maurice Canady -- who opted out for the 2020 season -- Rashard Robinson -- who will have to serve a two-game suspension for violating the performance-enhancing drug policy -- and perhaps last year's fourth-round pick, Reggie Robinson II, will have to impress early.

At defensive tackle, Antwaun Woods, who started 32 games in three seasons, was released in part because of his size (6-foot-1, 310 pounds), his pay ($2.1 million) and the addition of a true nose tackle in sixth-round pick Quinton Bohanna (6-4, 327).

Cowboys executive vice president Stephen Jones takes a little more conciliatory tone when it comes to the changes, believing the in-house talent is better than it performed collectively in 2020, which leans more toward a sign of the organization's displeasure with last year's coordinator, Mike Nolan.

With DeMarcus Lawrence, Smith, Vander Esch, Trevon Diggs, Jourdan Lewis (who re-signed at the start of free agency on a three-year deal), Neville Gallimore, Anthony Brown and Donovan Wilson, as well as Trysten Hill (who is coming back from a torn ACL), the Cowboys believe they have the players to make a competent group.

"I don't necessarily know that you've got to totally remake it in one offseason," Jones said. "What we did here today, yesterday and the day before was get guys who are going to be here for four or five years. They're going to complement what we did in free agency. I don't think you fix it overnight, but at the same time, I don't know if we needed to fix it overnight."

The newcomers, however, have the traits Quinn wants in defenders, such as speed and long arms and frames. Like the trend that has become vogue in the NBA, Quinn wants almost position-less players.

"When you have length, you can match some of that," Quinn said. "In the NFL, so many of the matchups are created on size or speed, so you want to have the roster that has versatility, and I think that's one of the things that I admire about Mike and having the versatility of positions where you play more than one thing."

Traits, however, will matter only if the player can play. Quinn is open to exceptions: "It's not one-size-fits-all."

The Cowboys' new players will have an advantage simply because they worked with Quinn in the past (Neal, Kazee) or fit what the Cowboys now want out of their defenders.

"As far as redoing one side of the ball, acquiring talent is really the first step," McCarthy said. "It's the beginning. The competition and pulling it all together, that's the fun part. That's the development of your football team. No matter how the numbers shake out, when we get to the 53[-man roster], the most important thing is that group is playing together, and that talent comes together.

"We'll be a better defense because of that."