Agreements on high end contracts aren't often reached as quickly as the Bears did with safety Eddie Jackson. Almost immediately after Jackson became eligible for a contract extension once the 2019 regular season ended, the Bears made him the NFL's highest-paid safety at $14,604,250 per year.

At the opposite end of the spectrum is Cowboys quarterback Dak Prescott. Negotiations for his new contract started over a year ago. The Cowboys have reportedly offered Prescott a contract making him the NFL's second highest-paid player behind Seahawks quarterback Russell Wilson's $35 million per year. The overall guarantees are on par with Rams quarterback Jared Goff's league record of $110,042,682.

A big sticking point is length of contract. The Cowboys are accustomed to doing lucrative deals where players sign for at least five new contract years. The most common length is six new years where players are under contract for a minimum of seven years since time has been remaining on the deals when signed. The recent trend is high end quarterback deals have been shorter than what Dallas would prefer. There are seven passers with contracts averaging $30 million or more per year. Falcons quarterback Matt Ryan is the only one whose deal contains more than four new contract years, as he signed a five-year contract extension.

A new variable in the equation is the potential impact the COVID-19 pandemic could have on the 2021 salary cap if league revenues decrease because games are played in empty stadiums. This prospect may lead to some teams to be cautious in signing core players to new contracts.

Here's a look at five potentially challenging veteran player contract negotiations besides Prescott's.

49ers TE George Kittle

A George Kittle extension has been an offseason priority for the 49ers. The expectation is Kittle will dramatically reset a tight end market that hasn't moved much since Jimmy Graham first hit the $10 million per year mark in 2014 with the Saints. The existing standard on a multi-year deal is the $42 million over four years Austin Hooper received from the Browns during free agency in March. Hooper's $23 million in guarantees and $18.5 million fully guaranteed at signing are the current benchmarks for tight ends.

Kittle would be justified in seeking to be paid like one of the game's best pass catchers regardless of position because of his production over the last two years. He is San Francisco's primary weapon in the passing game. In both 2018 and 2019, Kittle led the 49ers in receptions and receiving yards. He also tied for the team lead in touchdown catches. Kittle set the NFL single-season receiving yards record by a tight end in 2018 with 1,377 yards.

Since the beginning of the 2018 regular season, Kittle ranks 11th in the NFL with 173 receptions, and his 2,430 receiving yards are fifth most in the league. Kittle is one of nine players with at least 170 receptions and at least 2,000 receiving yards during this span. Wide receivers DeAndre Hopkins, Julio Jones and Michael Thomas are among those in this rather select group.

The long-term contracts of the NFL's 15 highest-paid pass catchers, all wide receivers, average approximately $16.375 million per year with close to $45 million in overall guarantees, where right around $25.75 million is fully guaranteed at signing. I doubt the 49ers have any intention of paying Kittle like a wide receiver.

Unfortunately for Kittle, NFL player salaries are constrained by position. The big exception is highly productive pass rushers. Players who can consistently put pressure on opposing quarterbacks are paid a premium whether a defensive end, defensive tackle or 3-4 outside linebacker. Chiefs perennial All-Pro Travis Kelce is the highest-paid tight end at just under $11.75 million per year after adjusting existing contracts for salary cap inflation.

Titans RB Derrick Henry

Titans general manager Jon Robinson is hoping to find common ground with Henry, who was designated a franchise player for $10.278 million, on a long-term deal. It wouldn't be surprising for Henry to view Christian McCaffrey's recent record-setting four-year extension with the Panthers averaging $16,015,053 per year as an indicator of the running back market after a stellar 2019 season.

Henry really made his mark in the playoffs during the Titans' run to the AFC Championship Game. He became the first player to ever have two games of at least 180 rushing yards in the same postseason. Henry also set an NFL record for the most rushing yards during a playoff run (not including the Super Bowl) with 446. His 148.7 rushing yards per game this postseason is the fourth-best mark ever in any single playoffs.

Henry led the NFL in rushing (1,540 yards) and tied for the league's most rushing touchdowns with 16 despite missing a game late in the season because of a hamstring injury. He earned his first Pro Bowl berth and was named to the Pro Football Writers of America's All-NFL team. Since the middle of the 2018 season, Henry has been the NFL's most productive ball-carrier. He has league bests of 2,299 rushing yards and 26 rushing touchdowns with 5.4 yards per carry.

Henry doesn't fit the profile of running backs who command top dollar. The bottom of the top tier is the $13 million per year the Cardinals gave David Johnson in 2018. Dual-threat running backs have been getting that type of money lately, but Henry doesn't add much in the passing game. He is more of a traditional ball-carrier from the previous era. Nonetheless, Henry is Tennessee's best offensive player.

The Titans have firsthand experience with how big money running contracts can backfire. Chris Johnson signed a four-year extension with the Titans averaging $13,493,750 per year and containing $30 million in guarantees after a lengthy pre-season holdout in 2011 when he had two years left on his rookie contract. He was released in 2014 after playing only one of the new contract years of his extension. In essence, the Titans paid Johnson $28.975 million in excess of his rookie contract to just have him for one additional season. The deal was before Robinson became general manager but Vice President of Football Administration Vin Marino, who handles player contracts, negotiated the deal.

Ravens OT Ronnie Stanley

The Texans didn't do the Ravens any favors by significantly raising the salary bar for offensive tackles by paying Laremy Tunsil $22 million per year on a three-year extension. Tunsil has an offensive-lineman record of $40 million fully guaranteed at signing. His overall guarantees are $50 million. Tunsil having a higher-than-expected average yearly salary on a shorter-than-anticipated term likely complicates Stanley's negotiations.

Stanley, who is scheduled to play the 2020 season on a $12.866 million fifth-year option, was selected seven picks before Tunsil in the 2016 NFL Draft with the sixth overall pick. Both were named to the Pro Bowl for the first time last season, with Stanley also earning first-team All-Pro honors. Outside of cornerback Marcus Peters, the Ravens aren't accustomed to doing high-end deals where players only give up three new years on extensions signed in the final year of rookie contracts or at their expiration. Unlike Tunsil, Peters had to sacrifice his average yearly salary to get the shorter term. It will be interesting to see how Stanley reaps the benefit of Tunsil dramatically resetting the offensive tackle market.

Chargers DE Joey Bosa

The Chargers and Bosa got off on the wrong foot during negotiations of his rookie contract in 2016. Bosa engaged in the longest incoming player holdout since the rookie wage scale was implemented in 2011. He signed a couple of days before the Chargers' final preseason game on September 1.

Bosa has more than lived up to being 2016's third overall pick. The 2016 NFL Defensive Rookie of the Year holds the NFL record for the most sacks in the first 20 games of a career with 19. He bounced back in 2019 from an injury-plagued 2018 season where a bone bruise in his left foot sidelined him for the first nine games. Bosa had his third double-digit sack season in four years, tying for ninth in the NFL with 11.5 sacks.

Expect more acrimony in negotiations for Bosa's second contract. Bosa, whose fifth-year option for this season is worth $14.36 million, will likely look to become the NFL's first $25 million per year non-quarterback, while the Chargers don't make a habit of signing players to market-setting deals.

Another holdout could be inevitable. Bosa has the same representation as Rams All-Pro interior defensive lineman Aaron Donald, CAA Sports' Bryan Ayrault. Donald engaged in two lengthy holdouts in 2017 and 2018 before signing his blockbuster deal, which made him the NFL's first $20 million per year non-quarterback.

The Browns have already started negotiations with 2017 first overall pick Myles Garrett. The defensive end is expected to replace Bears edge rusher Khalil Mack, who signed a six-year extension averaging $23.5 million per year with $90 million of guarantees ($60 million fully guaranteed at signing) in 2018, as the league's highest-paid non-quarterback. It's conceivable that Garrett could beat Bosa to the $25 million per year mark. Assuming Garrett signs first, Ayrault will surely look at the deal as Bosa's salary floor. Ayrault got an extremely player-friendly structure for Donald and will likely want to do something similar for Bosa.

Patriots G Joe Thuney

The Patriots putting a $14.781 million franchise tag on guard Joe Thuney wasn't an expected move, as a guard hadn't been given a franchise tag since the Patriots used one on Logan Mankins in 2011 until this year.

Thuney potentially could have become the NFL's highest-paid interior offensive lineman on the open market if recent history is any indication. A Pro Bowl caliber guard in his prime has been resetting the market in free agency (Andrew Norwell, Kelechi Osemele, Kevin Zeitler) for several years. The current standard is the four-year, $56.55 million extension averaging $14,137,500 per year Brandon Brooks received from the Eagles during the middle of last season.

Mike McCartney, Thuney's agent, has demonstrated a willingness to embrace the franchise tag through his representation of Vikings quarterback Kirk Cousins. Thurney quickly signed his franchise tender. McCartney surely recognizes that a second franchise tag for Thuney in 2021 at a CBA-mandated 20 percent increase would be $17,737,200.

A long-term deal must be attractive enough for Thuney to forego the possibility of hitting the open market next year since a second franchise tag might be too cost prohibitive. The Patriots haven't been afraid to let offensive linemen go during free agency (Trent Brown and Nate Solder) in recent years rather than set the market.