Dan Orlovsky says the Patriots' identity is centered on their run game and predicts New England will not pursue a receiver in the offseason. (1:03)

FOXBOROUGH, Mass. -- The only thing that stays constant in the NFL is change.

New England Patriots coach Bill Belichick has said something along those lines at various points of his 19-year tenure, most recently in the weeks leading up to Super Bowl LIII.

“There’s a lot of turnover in the National Football League on every team in every year. It’s the National Football League,” he said. “Teams turn over a lot of players and a lot of coaches every single year. Every. Single. Team.”

The defending Super Bowl champions won’t be an exception in 2019, as an Associated Press analysis of the past seven years showed that Super Bowl winners turned over an average of 20.4 players on their 53-man roster for Week 1 of the following season.

ESPN senior writer Mike Sando thoroughly dissected how the Patriots and Los Angeles Rams might look different in 2019 (ESPN+), and as a companion to that piece, let’s introduce the New England “free agent predictor” by assessing the odds for a return of key players with expiring contracts:

Stephen Gostkowski has been the Patriots' kicker for the past 13 seasons, and that seems likely to continue. Winslow Townson-USA TODAY Sports

Stephen Gostkowski

The second-longest-tenured player behind quarterback Tom Brady, Gostkowski was 27-of-32 on field goal attempts in the regular season (misses from 54, 50, 52, 48 and 42) and 49-of-50 on extra points. In the postseason, Gostkowski was 4-of-5 on field goals (miss from 46) and 10-of-10 on extra points.

Belichick has long expressed his appreciation for Gostkowski’s work (including kickoffs), which was reflected in the club making him the NFL’s highest-paid kicker in 2015 when signing him to a four-year, $17.2 million deal. That contract held up well over time relative to other kickers, and a similar pact would make sense this offseason, giving the 35-year-old Gostkowski a chance to go wire-to-wire in New England after initially arriving as a fourth-round draft choice in 2006. Odds of return: 90 percent

2019 NFL Free Agency Here's what to know:

• Most impactful moves for all 32 teams »

• Barnwell's lessons from free agency »

• Barnwell's grades: Tracking big moves »

• Winners and losers from free agency »

• Picking underrated, overrated signings »

More coverage » | Back to NFL »

Trey Flowers

The 6-foot-2, 265-pound Flowers is primed to cash in with a well-deserved big payday on the open market after leading the team in sacks in each of the past three seasons. His value to teams likely will vary depending on scheme, as he doesn’t fit the profile of a speed-rushing end who previously has commanded a top-of-the-market deal (e.g., Olivier Vernon).

But teams like the Patriots that play a multiple scheme and place a premium on players who can play a variety of techniques at a high level should see great appeal in the long-armed, soft-spoken Flowers. The 25-year-old is in his prime years and worthy of a big investment in New England, as he reflects, in many ways, what Belichick’s program is all about. One variable to consider: Having more coaches with roots in the Patriots’ system across the NFL (Brian Flores in Miami, Matt Patricia in Detroit, etc.) could help Flowers on the market. Odds of return: 70 percent

Ryan Allen

The Patriots’ punter since 2013, he saved his best for last in Super Bowl LIII, and it wouldn’t be surprising if that is the catalyst for an extension. Allen is also the holder for field goals and extra points, which adds to his value. The Patriots brought in some competition for Allen last offseason, signing undrafted rookie Corey Bojorquez, but Allen kept the job. While his leg might not be as strong as some others around the NFL, he’s shown a knack with situational punting, in which the Patriots place a high value. Odds of return: 70 percent

John Simon

Signing Simon in late September was one of the Patriots’ shrewdest acquisitions of the 2018 season, as his toughness to set the edge in a hybrid linebacker/defensive end role fit well in the team’s approach of varying its game plan on a weekly basis. He also added value on special teams. “Tweeners” like Simon generally have more value to the Patriots than most other teams, but similar to Flowers, it will be interesting to see how the presence of coaches with Patriots ties elsewhere affects his market. Odds of return: 60 percent

Jason McCourty might not be back, but he came through on a big stage in Super Bowl LIII. Fred Kfoury III/Icon Sportswire

Jason McCourty

It was hard to find anyone who had a negative thing to say about McCourty in 2018, as his leadership, experience and perspective were among the things cited by coaches and players over the course of the season. He also drew the start in the most important game of the season, Super Bowl LIII, making one of the plays of the game. So it’s easy to see a scenario in which the team would bring him back, although the cornerback crop is crowded with Stephon Gilmore, J.C. Jackson, Jonathan Jones (a restricted free agent projected to get an extension or the second-round tender) and 2018 second-round pick Duke Dawson all back. So any return likely would be at a team-friendly modest deal. Odds of return: 50 percent

Cordarrelle Patterson

With one rushing touchdown, one kickoff return for a touchdown and three receiving touchdowns, the sixth-year veteran receiver was a valuable “slash” option for the Patriots in 2018. Given how the Patriots place a high value on special teams, and how Patterson’s upbeat personality seemed like a positive addition to the locker room, the club figures to be in the mix to retain him, depending on how the market unfolds. Odds of return: 50 percent

Trent Brown

Things couldn’t have worked out much better for the 6-foot-8, 380-pound Brown, who started all 19 games at left tackle and showed he was capable of playing more than just the right side. With Nate Solder signing a deal worth $15 million per year with the Giants last offseason, Brown could make a case for a deal in that ballpark.

It's hard to imagine the Patriots making that type of investment, especially after selecting left tackle Isaiah Wynn in the first round of the 2018 draft (No. 23 overall) and having starting right tackle Marcus Cannon under contract for three more seasons on a solid contract. But if the market doesn’t materialize at that high level for Brown, the Patriots could be in the mix to retain him in a scenario that buys them some time to ensure that Wynn returns from an Achilles injury and performs at a high level. How things unfold with Brown also could factor into whether free-agent offensive tackle LaAdrian Waddle returns. Odds of return: 25 percent

Malcom Brown

The 2015 first-round draft choice (No. 32 overall) didn’t have his fifth-year option picked up for 2019 at around $8 million, which provides a financial ballpark for how the Patriots value him: He’s more of a two-down defensive tackle in their scheme. It’s possible that another team could view Brown as more of a three-down player based on playing a scheme that doesn’t rely as much on two-gap techniques. Odds of return: 25 percent

Chris Hogan

A true class act on the field and off it, Hogan’s three-year stint with the Patriots was a win-win situation for both him and the team. Signing a $12 million deal as a restricted free agent before the 2016 season was a financial breakthrough for him, and he won two Super Bowl rings as a key contributor. But the Patriots seemed to reveal their viewpoint of Hogan as more of a complementary piece than a foundation-type player by trading for Josh Gordon in September, then by having Gordon cut into Hogan’s playing time. So with Hogan set to hit the open market, it seems plausible that another team might value him at a higher level, perhaps also factoring in his veteran leadership and championship experience. Odds of return: 20 percent

Phillip Dorsett

Similar to Hogan, the Patriots seemed to tip their hand as to how they viewed Dorsett among their receivers based on the way 2018 unfolded: He was a starter earlier in the year before sliding into a supporting role following the acquisition of Gordon and return of Julian Edelman from suspension. He was valuable in that role, but it makes sense to think he’ll want to see if a greater opportunity exists elsewhere. If if Dorsett returns, it likely would be on a modest deal that reflects how the open market didn’t provide him a better opportunity with another club. Odds of return: 20 percent

Danny Shelton

The team’s third defensive tackle behind Lawrence Guy and Malcom Brown, he was inactive for three late-season games and the AFC Championship Game, which reflected how he was filling more of a niche role on the defense. But when the team went with more of a run-based approach, Shelton made some notable contributions, including in Super Bowl LIII. The Patriots didn’t pick up his fifth-year option for 2019, which would have paid him in the $8 million range. Odds of return: 15 percent