Some free agent signings are destined to change the trajectory of a franchise. Peyton Manning and Reggie White were the missing pieces that returned the Broncos and Packers, respectively, to glory. Drew Brees turned the Saints from rudderless also-ran into a world championship club. Curtis Martin jumped ship from the Patriots to become the Jets’ all-time leading rusher.

But for every natural fit, there are several more missed opportunities that made sense on paper but never came to fruition. Barry Sanders never left Detroit, instead choosing to re-sign with the team that shackled him to a 1-5 postseason record. Larry Fitzgerald’s unwavering loyalty to Arizona prevented him from playing in wide receiver Xanadu with Tom Brady and the Patriots. Franchises can share the blame for these missed opportunities, as well; Miami passed on signing Brees in favor of luring Daunte Culpepper to South Beach.

The 2017 free agent class has one surefire Hall of Famer hitting the market (Adrian Peterson), and the aging veteran is joined by several impact players who could be the difference between a potential revival and spending January packing up the locker room. Pro Bowlers like Dont’a Hightower, Calais Campbell, T.J. Lang, and Alshon Jeffery could all find new homes this spring with teams eager to get a head start on a winning campaign.

Some of these contracts will make total sense. Others will leave what looks like a perfect fit on the table to sign with teams that look like anything but an ideal landing spot. Here are the deals SB Nation’s NFL writers want to see most.

Eddie Lacy to the Patriots

LeGarrette Blount had a major role in the Patriots’ last two Super Bowl seasons, but while he scored a league-leading 18 touchdowns in 2016, he also ran for just 3.9 yards per carry and will be 31 years old by the end of next season. Even though the team can likely bring him back to the fold on a one-year contract — especially considering how poorly his last deal outside of New England went — Bill Belichick is no doubt considering a contingency plan at tailback.

The Patriots don’t typically spend money on runners, but Lacy’s unimpressive last two seasons in Green Bay have driven his value down. New England has a pair of effective backs under contract in Dion Lewis and James White, but neither is the pile-driving, hard-nosed runner that Lacy is at 235-plus pounds. Lacy is more than just a dynamic ball carrier, though; he caught 77 passes his first two seasons — years in which he also ran for more than 1,100 yards.

Lacy brings injury concerns, but at just 26 years old he could be set to bounce back and regain the form that made him a Pro Bowler as a rookie. He may not fit the Patriots’ typical free agent standard, but if the price is right he could be an upgrade, or an insurance policy, for an aging Blount. With just $3 million invested in tailbacks for 2017, the time could be right for New England to make an investment.

Likelihood of signing: Low. Both Lacy’s agent and Green Bay head coach Mike McCarthy have told reporters the Packers are interested in bringing the burly runner back. If his price is low enough for New England to pounce, it’s likely low enough for the Pack to retain him.

Logan Ryan to the Packers

Green Bay strikes back at New England’s theoretical swiping of Lacy by upgrading a position of dire need in 2017. The Packers ranked dead last in passing yards allowed last fall and 27th in opponent passer rating thanks to a secondary ravaged by injuries. Veteran Sam Shields is now gone, and while young players like Quinten Rollins and Damarious Randall have potential, Green Bay needs a steady presence to tie the team’s coverage together.

Enter Ryan, who started 27 games the past two seasons while recording 25 defensed passes in that span. The 2013 third-round pick teamed with All-Pros Malcolm Butler and Devin McCourty to form a top-10 passing defense -- though the Patriots were rarely tested by high-level quarterbacks last fall. The free agent corner hasn’t missed a game in his NFL career, which would be a boon for a Green Bay team that only had one cornerback, Ladarius Gunter, play in all 16 regular season contests last fall.

Likelihood of signing: Medium. The Packers rarely make a big splash in free agency, but have rarely been as deficient at one position as they were at corner last fall. Ryan will command a big salary as one of the best free agent defensive backs on the market, but at 26 years old, a big investment could be worthwhile.

Mike Glennon to the Bears

Three quarterbacks split the starting quarterback job for the Bears and they collectively threw 19 touchdowns with 19 interceptions. The most disappointing of the trio was Jay Cutler, once anointed the franchise quarterback in Chicago after the team made a big trade to acquire him from the Denver Broncos. But that deal never worked out as planned, and Cutler’s days with the Bears are almost certainly through.

Glennon may seem like an odd solution to that problem, considering his 5-13 record as a starter, but some believe he’s ready to be a big-time player for a team. His former teammate, Dan Orlovsky, said that after spending time in practices and games with Glennon he believes the 2013 third-round pick is a “starting QB all day long.”

And considering the price range Glennon is expected to be at, NFL teams believe the 6’7 quarterback is a starter, too. Charles Robinson of Yahoo expects Glennon to receive a contract that averages about $14 to $15 million per year. While that sounds like a ludicrous amount for the Bears to pony up, it wouldn’t even put him in the top 20 highest-paid quarterbacks in the NFL.

Giving Glennon a deal similar to the one that Brock Osweiler received in 2016 could give the Bears a promising, 27-year-old option at quarterback who doesn’t break the bank and could receive an even richer deal if he proves his worth.

Likelihood of signing: High. There’s already a lot of smoke and the rumors could be the sign of a real fire. NFL Network’s Ian Rapoport says the Bears plan to make a “major push” for Glennon and Chicago is the quarterback’s “preferred spot.” There aren’t many teams that need a quarterback more than the Bears, and the team has more than $50 million in cap space to make the deal happen.

Terrelle Pryor re-signing with the Browns

Pryor was the Browns’ leading receiver last year, and he made it clear that he wants to remain in Cleveland and help Hue Jackson improve the team. That’s why it’s a little perplexing that the Browns appear to be willing to let him walk in free agency.

It wasn’t just that Pryor was Cleveland’s top receiver, racking up 1,007 yards and four touchdowns in 2016. No other receiving option on the roster came close to Pryor’s productivity last season. Tight end Gary Barnidge was closest, with 612 receiving yards and two touchdowns.

Pryor did this in a season that featured six different quarterbacks throwing passes for the Browns because of consistent injuries. One of the six was Pryor, who completed five of nine passes for 41 yards.

A sticking point for Cleveland was Pryor’s asking price, which is around $10 million per year. The Browns were reportedly willing to pay about $8 million per year, but they also have about $102 million in cap space available. Being stingy in this situation makes little sense.

Likelihood of signing: Medium. It makes perfect sense for the Browns to get something done with Pryor, but they had the opportunity to tag him or apply the transition tag, and they didn’t do any of those things. They shouldn’t let Pryor walk over $2 million per year, but as Mocking the Draft’s Dan Kadar noted, losing Pryor would be “a pretty Browns-ass way to start the new league year.”

Adrian Peterson to the Raiders

Maybe the biggest name on the market, Peterson isn’t going to get paid like it — not at age 32 with a lengthy injury history that includes a knee surgery that sidelined him for most of 2016. He’s shown superhuman recovery ability in the past, but there’s no doubt that the end of Peterson’s career is on the horizon.

If he ends up leaving the Vikings, he’ll likely want it to be with a contender with an offensive line much better than Minnesota’s, which made way for the NFL’s worst rushing attack in 2016.

The Raiders can be that team. Prior to a whole bunch of injuries that derailed Oakland’s 2016 season, the team was a Super Bowl contender and boasted one of the most intimidating and powerful offensive lines. If Peterson has anything left in the gas tank, the Raiders’ inexperienced running back corps could use the addition.

Likelihood of signing: Medium. Peterson reportedly likes the idea of playing for the Raiders, but he’s really not calling the shots at this point. It will depend on if the Raiders believe there’s tread left on the tires and if the price is right, although Oakland should have no problem picking up any amount.

Alshon Jeffery to the Eagles

Despite missing a good portion of 2015 due to injury and four games in 2016 thanks to a PED suspension, Jeffery could still have a long future in the NFL. The wide receiver spent his first five seasons in the league with the Chicago Bears and a less-than-ideal — and reliable — quarterback situation. Even still, he was able to secure two consecutive 1,000-yard seasons and a roster spot in the 2013 Pro Bowl.

The Eagles are in a precarious situation offensively and need to bring in some young talent around quarterback Carson Wentz. With current targets that include Nelson Agholor and Dorial Green-Beckham, Philadelphia had the fifth-highest drop rate in the league last season — not to mention an aging and injured group of running backs. While the team will add some depth during the NFL draft, they still need to make some moves in free agency to revive the roster.

Jeffery played under the franchise tag in 2016, worth $14.599 million. And while he’ll likely be looking for similar money moving forward, that would still be in the Eagles’ price range and a good bailout option for Wentz downfield.

Likelihood of signing: Medium. Jeffery could benefit from having a steady quarterback to work with, and Wentz desperately needs some dependability at the receiver position. The Eagles reportedly tried to trade for Jeffery midseason in 2016 to avoid a free agency bidding war, but didn’t end up coming close to a deal.